| | AddedJcastle | Prefecture | City | Contributor | Castle Type | Castle Condition |
|---|
| Aburakawa Nobue Yashiki | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Ahoyama Castle | 2024 | Shiga Prefecture | Otsu | Eric | Mountaintop | Ruins only |
| Aida Yakata | 2022 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Aika Yashiki | 2025 | Shizuoka Prefecture | Iwata | ART | Fortified Manor | Ruins only |
| Aiki Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Aimiyamamonomi Fort | 2022 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Ainuta Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Aizu Wakamatsu Castle | 1999 | Fukushima Prefecture | Aizu Wakamatsu | Eric | Hilltop | Reconstructed main keep |
| Akagi Kita Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Akagi Minami Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Akagi Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Akahori Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Fortified Manor | Ruins only |
| Akaiwa Castle | 2025 | Aichi Prefecture | Toyohashi | ART | Mountaintop | Ruins only |
| Akasaka Jin'ya | 2023 | Aichi Prefecture | Toyokawa | ART | Fortified Manor | No main keep but other buildings |
| Akashi Castle | 2007 | Hyogo Prefecture | Akashi | Eric | Hilltop | No main keep but other buildings |
| Akashibu Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Akasu Castle (Ina) | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Akatsuka Castle | 2020 | Tokyo | Tokyo | Eric | Hilltop | Ruins only |
| Akayama Jin'ya | 2023 | Saitama Prefecture | Kawaguchi | Eric | Flatland | Ruins only |
| Akazawa Yakata | 2022 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Akechi Castle | 2025 | Gifu Prefecture | Ena | ART | Mountaintop | No main keep but other buildings |
| Akechi Jin'ya | 2025 | Gifu Prefecture | Ena | ART | Hilltop | Ruins only |
| Akechi Osayama Castle | 2021 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Aki Castle | 2013 | Kochi Prefecture | Aki City | | Hilltop | Ruins only |
| Akiba Fort (Azumi) | 2023 | Nagano Prefecture | Hakuba | ART | Mountaintop | Ruins only |
| Akiba Fort (Ina) | 2021 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Akita Castle | 2012 | Akita Prefecture | Akita City | Frank T. | Flatland | No main keep but other buildings |
| Akiyama Yakata | 2023 | Yamanashi Prefecture | Minami-Alps | ART | Fortified Manor | Ruins only |
| Akiyoshi Fort | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Akizuki Castle | 2009 | Fukuoka Prefecture | Asakura | Kyushudan | Flatland | No main keep but other buildings |
| Akizuki Domain South Detached Palace | 2020 | Fukuoka Prefecture | Asakura | ART | Flatland | Ruins only |
| Ako Castle | 2009 | Hyogo Prefecture | Ako | Eric | Flatland | No main keep but other buildings |
| Akozu Castle | 2016 | Akita Prefecture | Yurihonjo | ART | Mountaintop | No main keep but other buildings |
| Akutagawasan Castle | 2013 | Osaka | Takatsuki | RaymondW | Mountaintop | Ruins only |
| Amabiki Castle | 2022 | Nagano Prefecture | Takayama | ART | Mountaintop | Ruins only |
| Amaga Castle | 2012 | Miyazaki Prefecture | Takaoka-cho | Frank T. | Mountaintop | Reconstructed main keep |
| Amagasaki Castle | 2013 | Hyogo Prefecture | Amagasaki | Eric | Flatland | Reconstructed main keep |
| Amagata Castle | 2025 | Shizuoka Prefecture | Mori | ART | Mountaintop | Ruins only |
| Amanari Castle | 2023 | Yamanashi Prefecture | Fujikawa | ART | Mountaintop | Ruins only |
| Amari Yakata | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Amemiya Yashiki | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Ametoya Castle | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Amidadou Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Amidagamine Castle (Yamashiro) | 2022 | Kyoto | Kyoto | ART | Mountaintop | Ruins only |
| Amino Shingozaemon Yashiki | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Amino Yashiki | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Anjou Jin'ya | 2023 | Aichi Prefecture | Anjō | ART | Flatland | Ruins only |
| Annaka Castle | 2018 | Gunma Prefecture | Annaka | Eric | Hilltop | No main keep but other buildings |
| Ano Yakata | 2023 | Shizuoka Prefecture | Numazu | ART | Fortified Manor | Ruins only |
| Anrakuji Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Ansho Castle | 2009 | Aichi Prefecture | Anjo | Eric | Flatland | Ruins only |
| Anshouko Castle | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Aoiyama Castle | 2023 | Fukui Prefecture | Obama | ART | Mountaintop | Ruins only |
| Aoki Castle (Azumi) | 2021 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Aoki Castle (Sakata) | 2022 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Aono Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Aoyagi Castle | 2016 | Nagano Prefecture | Chikuhokumura | Eric | Mountaintop | No main keep but other buildings |
| Aoyagi Yakata | 2022 | Nagano Prefecture | Chikuhoku | ART | Fortified Manor | Ruins only |
| Aoyama Castle | 2015 | Saitama Prefecture | Ogawamachi | Eric | Mountaintop | Ruins only |
| Aoyama Castle (Nagato) | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Mountaintop | Ruins only |
| Aoyama Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Hilltop | Ruins only |
| Aoyama Yashiki (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ara Castle (Ina) | 2022 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Ara Castle (Murakami Clan Fort Network) | 2021 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Aragaito Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Arahorinaiki Yashiki | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Arai Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Araihara Castle | 2023 | Nagano Prefecture | Takayama | ART | Mountaintop | Ruins only |
| Araino Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Arako Castle | 2020 | Aichi Prefecture | Nagoya | ART | Flatland | Ruins only |
| Arashi Castle | 2020 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Aratame Castle | 2023 | Yamagata Prefecture | Sakata | ART | Flatland | Ruins only |
| Arato Castle | 2008 | Nagano Prefecture | Chikuma | Eric | Mountaintop | No main keep but other buildings |
| Aratoshou Castle | 2021 | Nagano Prefecture | Chikuma | ART | Mountaintop | Ruins only |
| Arayama Castle | 2019 | Ishikawa Prefecture | Nakanoto | ART | Mountaintop | Ruins only |
| Arikoyama Castle | 2013 | Hyogo Prefecture | Toyooka | Eric | Mountaintop | Ruins only |
| Aruga Castle | 2020 | Nagano Prefecture | Suwa | ART | Mountaintop | Ruins only |
| Asaba Castle | 2016 | Gunma Prefecture | Kanra | Eric | Mountaintop | Ruins only |
| Asada Castle (Chikuma) | 2020 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Asahara Yakata | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Asahi Castle (Chikuma) | 2019 | Nagano Prefecture | Asahi | ART | Mountaintop | Ruins only |
| Asahi Castle (Minochi) | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Asahi Castle (Owari) | 2019 | Aichi Prefecture | Owari-Asahi | ART | Mountaintop | Reconstructed main keep |
| Asahi Moated Settlement | 2024 | Aichi Prefecture | Kiyosu | ART | Flatland | No main keep but other buildings |
| Asahiyama Castle | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Asahiyama Castle (Kai) | 2022 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Asaka Castle (Chikuma) | 2021 | Nagano Prefecture | Chikuhoku | ART | Mountaintop | Ruins only |
| Asakura Yakata | 2023 | Fukui Prefecture | Fukui | Eric | Fortified Manor | No main keep but other buildings |
| Asama Palace | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Asama Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Asano Castle | 2025 | Aichi Prefecture | Ichinomiya | ART | Flatland | Ruins only |
| Ashigara Castle | 2010 | Shizuoka Prefecture | Oyama | Eric | Mountaintop | Ruins only |
| Ashikaga Masauji Yakata | 2023 | Saitama Prefecture | Kuki | Eric | Fortified Manor | Ruins only |
| Ashikagashi Yakata | 2007 | Tochigi Prefecture | Ashikaga | Eric | Fortified Manor | No main keep but other buildings |
| Ashimori Jin'ya | 2022 | Okayama Prefecture | Okayama | ART | Flatland | No main keep but other buildings |
| Ashinoya Jin'ya | 2023 | Aichi Prefecture | Kōta | ART | Flatland | No main keep but other buildings |
| Asonuma Castle | 2017 | Tochigi Prefecture | Sano | Eric | Flatland | Ruins only |
| Asou Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Asouko Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Asukayama Castle | 2022 | Tokyo | Tokyo | Eric | Hilltop | Ruins only |
| Asuke Castle | 2017 | Aichi Prefecture | Toyota | Furinkazan | Mountaintop | Reconstructed main keep |
| Asuke Jin'ya | 2024 | Aichi Prefecture | Toyota | ART | Flatland | Ruins only |
| Atagoyama Noroshidai | 2023 | Yamanashi Prefecture | Kōfu | ART | Mountaintop | Ruins only |
| Atsushiba Yashiki (Koma) | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Awaji Castle (Chikuma) | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Awaya Yakata | 2023 | Fukui Prefecture | Mihama | ART | Fortified Manor | Ruins only |
| Awazawa Castle (Suwa) | 2023 | Nagano Prefecture | Chino | ART | Hilltop | Ruins only |
| Aya Castle | 2007 | Miyazaki Prefecture | Aya | | Mountaintop | Reconstructed main keep |
| Ayukawa Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Azai Higashi Castle | 2023 | Aichi Prefecture | Nishio | ART | Fortified Manor | Ruins only |
| Azai Nishi Castle | 2023 | Aichi Prefecture | Nishio | ART | Fortified Manor | No main keep but other buildings |
| Azuchi Castle | 2004 | Shiga Prefecture | Azuchi | Eric | Hilltop | Ruins only |
| Baba Noroshidai | 2025 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Baba Yashiki | 2019 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | No main keep but other buildings |
| Baba Yashiki (Kai) | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | No main keep but other buildings |
| Banba Castle | 2025 | Shiga Prefecture | Maibara | ART | Mountaintop | Ruins only |
| Beffu Castle (Koka) | 2021 | Shiga Prefecture | Kouka | ART | Fortified Manor | Ruins only |
| Binmanji Castle | 2024 | Shiga Prefecture | Taga | ART | Hilltop | Ruins only |
| Bitchu Matsuyama Castle | 2004 | Okayama Prefecture | Takahashi | Eric | Mountaintop | Original main keep |
| Bitchu Takamatsu Castle | 2012 | Okayama Prefecture | Okayama City | Phibbyfan | Flatland | Ruins only |
| Biwa Castle (Kai) | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Bizen Date (Uzen) | 2023 | Yamagata Prefecture | Tsuruoka | ART | Fortified Manor | Ruins only |
| Bizenhara Yakata | 2022 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Bodaiyama Castle | 2025 | Gifu Prefecture | Tarui | ART | Mountaintop | Ruins only |
| Bue Yakata (Totomi) | 2024 | Shizuoka Prefecture | Kikugawa | ART | Fortified Manor | Ruins only |
| Busetsu Castle | 2022 | Aichi Prefecture | Toyota | 豪谷 | Mountaintop | Ruins only |
| Bushihara Fort | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Chamachi Battery (Obama Domain) | 2023 | Fukui Prefecture | Tsuruga | ART | Flatland | Ruins only |
| Chausudate | 2021 | Akita Prefecture | Noshiro | Eric | Mountaintop | Ruins only |
| Chausuyama Castle (Chikuma) | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Chausuyama Castle (Nukata) | 2024 | Aichi Prefecture | Kōta | ART | Mountaintop | Ruins only |
| Chausuyama Castle (Shinano) | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Chiba Castle | 2009 | Chiba Prefecture | Chiba | Eric | Hilltop | Reconstructed main keep |
| Chifuruya Castle (Sanada) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Chigasaki Castle | 2009 | Kanagawa Prefecture | Yokohama | Eric | Hilltop | Ruins only |
| Chihaya Castle | 2014 | Osaka | Osaka | Phibbyfan | Mountaintop | Ruins only |
| Chikaoka Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Chikatou Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Chikuma Goten'yama Castle | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Chikusa Castle | 2024 | Mie Prefecture | Komono | ART | Mountaintop | Ruins only |
| Chikuzenbara Fort | 2022 | Yamanashi Prefecture | Fuefuki | ART | Flatland | Ruins only |
| Chimura Yashiki | 2021 | Gifu Prefecture | Kani | ART | Fortified Manor | Ruins only |
| Chinaha Castle | 2024 | Okinawa Prefecture | Kumejima | RaymondW | Hilltop | Ruins only |
| Chinen Castle | 2023 | Okinawa Prefecture | Nanjo City | RaymondW | Mountaintop | Ruins only |
| Chiran Castle | 2013 | Kagoshima Prefecture | Minami Kyushu | Frank T. | Hilltop | Ruins only |
| Chofuku Castle | 2018 | Tochigi Prefecture | Oyama | Eric | Flatland | Ruins only |
| Chouja Yashiki (Totomi) | 2025 | Shizuoka Prefecture | Iwata | ART | Fortified Manor | Ruins only |
| Choujaike Yakata | 2022 | Nagano Prefecture | Ikeda | ART | Fortified Manor | Ruins only |
| Choujayama Castle | 2020 | Ibaraki Prefecture | Mito | ART | Hilltop | Ruins only |
| Choujayashiki Yakata | 2020 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Choukokuji Fort | 2025 | Yamanashi Prefecture | Fuefuki | ART | Mountaintop | Ruins only |
| Chousenji Fort | 2023 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Choushouin Yakata | 2020 | Nagano Prefecture | Omachi | ART | Fortified Manor | Ruins only |
| Chouzenjimae Jin'ya | 2021 | Yamanashi Prefecture | Koufu | ART | Flatland | Ruins only |
| Daikan Yashiki | 2025 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Daikan'yama Fort | 2022 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Daikan'yashiki Castle | 2025 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Daikannon Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Dainenji Yakata | 2020 | Nagano Prefecture | Omachi | ART | Fortified Manor | Ruins only |
| Daita Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Daiun'in Doi | 2022 | Shizuoka Prefecture | Gotemba | ART | Fortified Manor | No main keep but other buildings |
| Damine Castle | 2023 | Aichi Prefecture | Shitara | Furinkazan | Mountaintop | No main keep but other buildings |
| Damine Yashiki | 2023 | Aichi Prefecture | Shitara | ART | Fortified Manor | Ruins only |
| Dannoura Battery | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Flatland | Ruins only |
| Deura Castle | 2022 | Nagano Prefecture | Sakaki | ART | Mountaintop | Ruins only |
| Do Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Dodo Fort | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Dohiyama Castle (Nagato) | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Fortified Manor | Ruins only |
| Doi Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Doi Tono Yashiki | 2025 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Dokanyama | 2022 | Tokyo | Tokyo | Eric | Mountaintop | Ruins only |
| Dokyou Castle | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Dota Castle (Mino) | 2025 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Doudo Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Dousawa Fort | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Doushou Hori | 2023 | Yamanashi Prefecture | Tsuru | ART | Flatland | Ruins only |
| Ebe Castle (Omi) | 2022 | Shiga Prefecture | Yasu | ART | Fortified Manor | Ruins only |
| Eboshigata Castle | 2023 | Osaka | Kawachinagano | Eric | Mountaintop | Ruins only |
| Echizen Katsuyama Castle | 2010 | Fukui Prefecture | Katsuyama | Furinkazan | Flatland | Reconstructed main keep |
| Echizen Ohno Castle | 2007 | Fukui Prefecture | Ohno | RaymondW | Mountaintop | Reconstructed main keep |
| Edo Castle | 1999 | Tokyo | Tokyo | Eric | Hilltop | No main keep but other buildings |
| Egawa Fort | 2021 | Shizuoka Prefecture | Izunokuni | ART | Mountaintop | Ruins only |
| Eimeiin Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Ema Yakata | 2019 | Gifu Prefecture | Hida | ART | Fortified Manor | No main keep but other buildings |
| Enryakuji | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | No main keep but other buildings |
| Enryakuji Amidadou Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | No main keep but other buildings |
| Enryakuji Higashitani Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | Ruins only |
| Enryakuji Joudoin Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | No main keep but other buildings |
| Enryakuji Kitatani Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | Ruins only |
| Enryakuji Monjurou Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | No main keep but other buildings |
| Enryakuji Nishitani Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | Ruins only |
| Enryakuji Shakadou Fort | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | No main keep but other buildings |
| Fubukikaito Castle (Ina) | 2022 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Fuchu Castle (Hitachi) | 2022 | Ibaraki Prefecture | Ishioka | ART | Flatland | No main keep but other buildings |
| Fudoudou Yakata | 2023 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Fujihashi Castle (Tokyo) | 2015 | Tokyo | Oume | Eric | Hilltop | Ruins only |
| Fujii Castle (Mikawa) | 2025 | Aichi Prefecture | Anjo | ART | Flatland | Ruins only |
| Fujikake Jin'ya | 2024 | Kyoto | Ayabe | Eric | Flatland | Ruins only |
| Fujikawa Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Fujimaki Castle | 2023 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Fujimaki Yashiki | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Fujimaru Yakata | 2024 | Shizuoka Prefecture | Kikugawa | ART | Fortified Manor | Ruins only |
| Fujita Castle | 2017 | Fukushima Prefecture | Ishikawa | ART | Hilltop | No main keep but other buildings |
| Fukakusa Yakata | 2020 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Fukayama Castle (Suruga) | 2023 | Shizuoka Prefecture | Susono | ART | Mountaintop | Ruins only |
| Fukazawa Castle | 2014 | Shizuoka Prefecture | Gotenba | Eric | Flatland | No main keep but other buildings |
| Fukigabora Castle | 2025 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Fukouzu Castle | 2024 | Aichi Prefecture | Kōta | ART | Flatland | No main keep but other buildings |
| Fukuchiyama Castle | 2009 | Kyoto | Fukuchiyama | RaymondW | Hilltop | Reconstructed main keep |
| Fukui Castle | 2006 | Fukui Prefecture | Fukui City | Eric | Flatland | No main keep but other buildings |
| Fukui Castle (Shinano) | 2023 | Nagano Prefecture | Takayama | ART | Flatland | Ruins only |
| Fukujima Castle (Takai) | 2022 | Nagano Prefecture | Suzaka | ART | Flatland | Ruins only |
| Fukuju Fort (Odani Castle) | 2024 | Shiga Prefecture | Nagahama | ART | Mountaintop | Ruins only |
| Fukuoka Castle | 2006 | Fukuoka Prefecture | Fukuoka City | Kyushudan | Hilltop | No main keep but other buildings |
| Fukuouji Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Fukurouga Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Fukushima Castle | 2016 | Fukushima Prefecture | Fukushima City | ART | Flatland | Ruins only |
| Fukushima Castle (Echigo) | 2017 | Niigata Prefecture | Jōetsu | ART | Flatland | Ruins only |
| Fukushima Castle (Kiso) | 2020 | Nagano Prefecture | Kiso | ART | Mountaintop | Ruins only |
| Fukutake Castle (Chikuzen) | 2020 | Fukuoka Prefecture | Asakura | ART | Mountaintop | Ruins only |
| Fukuyama Castle | 2006 | Hiroshima Prefecture | Fukuyama | Eric | Hilltop | Reconstructed main keep |
| Fukuyo Castle | 2020 | Nagano Prefecture | Minowa | ART | Hilltop | Ruins only |
| Fukuzawa Yakata | 2022 | Nagano Prefecture | Sakaki | ART | Fortified Manor | Ruins only |
| Fukuzuka Castle (Mino) | 2022 | Gifu Prefecture | Wanōchi | 豪谷 | Flatland | Ruins only |
| Fumimichi Castle | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Reconstructed main keep |
| Funagatayama Castle | 2025 | Aichi Prefecture | Toyohashi | ART | Mountaintop | Ruins only |
| Funage Castle | 2024 | Hyogo Prefecture | Akashi | Eric | Flatland | Ruins only |
| Funai Castle | 2012 | Oita Prefecture | Oita City | Frank T. | Flatland | No main keep but other buildings |
| Funaki Castle (Omi) | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Flatland | Ruins only |
| Funaoka Castle | 2017 | Miyagi Prefecture | Shibata | ART | Mountaintop | Ruins only |
| Funaokayama Castle | 2020 | Kyoto | Kyoto | ART | Mountaintop | Ruins only |
| Funayama Castle | 2019 | Hiroshima Prefecture | Akitakata | Eric | Mountaintop | Ruins only |
| Funayama Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Funehiki Castle | 2016 | Fukushima Prefecture | Tamura City | ART | Hilltop | Ruins only |
| Furuhata Yakata | 2022 | Nagano Prefecture | Kiso | ART | Fortified Manor | Ruins only |
| Furui Castle (Mikawa) | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Furujiro Fort | 2025 | Yamanashi Prefecture | Fuefuki | ART | Mountaintop | Ruins only |
| Furujou Yakata | 2021 | Nagano Prefecture | Ômachi | ART | Fortified Manor | Ruins only |
| Furujouyama Castle (Hanishina) | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Furukawa Castle | 2022 | Gifu Prefecture | Hida | 豪谷 | Hilltop | Ruins only |
| Furumaya Castle (Azumi) | 2021 | Nagano Prefecture | Azumino | ART | Flatland | Ruins only |
| Furumaya Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Furumiya Castle | 2023 | Aichi Prefecture | Shinshiro | ART | Hilltop | Ruins only |
| Furumiya Castle (Kai) | 2023 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Furusutobaru Ruins | 2024 | Okinawa Prefecture | Ishigaki | RaymondW | Hilltop | Ruins only |
| Furuwatari Castle | 2020 | Aichi Prefecture | Nagoya | ART | Flatland | Ruins only |
| Fuse Castle (Sarashina) | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Fuseya Castle | 2024 | Gifu Prefecture | Ginan | ART | Flatland | Ruins only |
| Fuseyachouja Yakata | 2022 | Nagano Prefecture | Fujimi | ART | Fortified Manor | Ruins only |
| Fushimi Castle | 2004 | Kyoto | Kyoto | Eric | Flatland | Reconstructed main keep |
| Fusou Castle (Mikawa) | 2023 | Aichi Prefecture | Gamagôri | ART | Mountaintop | Ruins only |
| Fusumada Castle | 2023 | Kanagawa Prefecture | Sagamihara | ART | Mountaintop | Ruins only |
| Futae Castle (Azumi) | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Futamata Castle | 2010 | Shizuoka Prefecture | Hamamatsu | Eric | Mountaintop | Ruins only |
| Futatsu Bungonokami Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Futatsugi Castle (Azumi) | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Futoge Castle | 2017 | Ishikawa Prefecture | Hakusan | Furinkazan | Mountaintop | Ruins only |
| Futoh'yama Castle | 2020 | Shiga Prefecture | Maibara | ART | Mountaintop | Ruins only |
| Futsukamachi Castle | 2024 | Gifu Prefecture | Gujō | ART | Mountaintop | Ruins only |
| Futta Castle (Suwa) | 2023 | Nagano Prefecture | Chino | ART | Fortified Manor | Ruins only |
| Fuwa no Seki | 2024 | Gifu Prefecture | Sekigahara | ART | Flatland | Ruins only |
| Gakiyama Noroshidai | 2021 | Nagano Prefecture | Suwa | ART | Mountaintop | Ruins only |
| Gakuden Castle (Owari) | 2020 | Aichi Prefecture | Inuyama | ART | Flatland | Ruins only |
| Ganjaku Castle | 2013 | Fukuoka Prefecture | Soeda | Furinkazan | Mountaintop | Reconstructed main keep |
| Ganryakuji Castle | 2023 | Aichi Prefecture | Toyokawa | ART | Mountaintop | Ruins only |
| Ganshouin Yakata | 2022 | Nagano Prefecture | Obuse | ART | Fortified Manor | Ruins only |
| Garyuzan Castle | 2024 | Gifu Prefecture | Kaizu | ART | Mountaintop | No main keep but other buildings |
| Gassan Toda Castle | 2011 | Shimane Prefecture | Yasugi | Eric | Mountaintop | No main keep but other buildings |
| Genbao Castle | 2023 | Fukui Prefecture | Tsuruga | Eric | Mountaintop | Ruins only |
| Genga Yashiki (Kai) | 2022 | Yamanashi Prefecture | Shōwa | ART | Fortified Manor | Ruins only |
| Genji Yakata (Kai) | 2021 | Yamanashi Prefecture | Ichikawamisato | ART | Fortified Manor | Ruins only |
| Gentairi Castle | 2023 | Nagano Prefecture | Suzaka | ART | Mountaintop | Ruins only |
| Gifu Castle | 1999 | Gifu Prefecture | Gifu | Eric | Mountaintop | Reconstructed main keep |
| Gion Castle | 2018 | Tochigi Prefecture | Oyama | Eric | Flatland | Ruins only |
| Gobara Castle | 2016 | Gunma Prefecture | Higashiazuma | Eric | Mountaintop | Ruins only |
| Gochaku Castle | 2020 | Hyogo Prefecture | Himeji | Eric | Flatland | Ruins only |
| Goi Castle (Mikawa) | 2023 | Aichi Prefecture | Gamagôri | ART | Hilltop | No main keep but other buildings |
| Gokan Castle | 2016 | Gunma Prefecture | Annaka | Eric | Mountaintop | Ruins only |
| Goma Nakamura Castle | 2025 | Kyoto | Nantan | Eric | Mountaintop | Ruins only |
| Gongen Yakata | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Gongen'yama Castle (Mino) | 2025 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Goryokaku Fort | 2002 | Hokkaido | Hakodate | Eric | Flatland | No main keep but other buildings |
| Goryoudaira Fort | 2023 | Yamanashi Prefecture | Hokuto | ART | Flatland | Ruins only |
| Goryu Castle | 2023 | Hiroshima Prefecture | Akitakata | Eric | Mountaintop | Ruins only |
| Gouda Fort | 2021 | Toyama Prefecture | Kamiichi | ART | Mountaintop | Ruins only |
| Goudo Castle | 2025 | Gifu Prefecture | Mitake | ART | Flatland | Ruins only |
| Goudo Noroshidai | 2025 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Gujo Hachiman Castle | 2004 | Gifu Prefecture | Gujo Hachiman | Eric | Mountaintop | Reconstructed main keep |
| Gushikawa Castle (Itoman Okinawa) | 2023 | Okinawa Prefecture | Itoman City | RaymondW | Flatland | Ruins only |
| Gushikawa Castle (Kumejima Okinawa) | 2024 | Okinawa Prefecture | Kumejima | RaymondW | Hilltop | Ruins only |
| Ha Castle | 2023 | Aichi Prefecture | Hekinan | ART | Flatland | No main keep but other buildings |
| Haba Castle | 2020 | Nagano Prefecture | Tatsuno | ART | Hilltop | Ruins only |
| Habako Castle | 2022 | Nagano Prefecture | Tatsuno | ART | Hilltop | Ruins only |
| Habauehori Yashiki | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Habu Castle | 2024 | Kyoto | Nantan | Eric | Mountaintop | Ruins only |
| Hachigata Castle | 2006 | Saitama Prefecture | Yorii | Eric | Hilltop | No main keep but other buildings |
| Hachikenchōja Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Hachiman'yama Castle (Tanba) | 2021 | Hyogo Prefecture | Tanba | ART | Mountaintop | Ruins only |
| Hachimanpara Jinsho | 2023 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Hachimanshita Battery (Obama Domain) | 2023 | Fukui Prefecture | Obama | ART | Flatland | Ruins only |
| Hachinohe Castle | 2010 | Aomori Prefecture | Hachinohe | Eric | Hilltop | No main keep but other buildings |
| Hachioji Castle | 2002 | Tokyo | Hachioji | Eric | Mountaintop | Ruins only |
| Hadanashi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Hadanashiyama Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Haga Castle | 2011 | Hyogo Prefecture | Shiso | Frank T. | Mountaintop | No main keep but other buildings |
| Hagi Castle | 2007 | Yamaguchi Prefecture | Hagi | Eric | Flatland | No main keep but other buildings |
| Hagikura Fort | 2020 | Nagano Prefecture | Shimo-Suwa | ART | Mountaintop | Ruins only |
| Hagiwarasuwa Castle | 2022 | Gifu Prefecture | Gero | 豪谷 | Flatland | Ruins only |
| Haguro Castle (Owari) | 2020 | Aichi Prefecture | Inuyama | ART | Fortified Manor | Ruins only |
| Haibara Castle | 2016 | Nagano Prefecture | Matsumoto | Eric | Mountaintop | Ruins only |
| Haiyama Castle | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Hajikamigou Castle | 2023 | Aichi Prefecture | Toyohashi | ART | Fortified Manor | Ruins only |
| Hajoudo Castle | 2023 | Aichi Prefecture | Kariya | ART | Fortified Manor | Ruins only |
| Hajoudoko Castle | 2024 | Aichi Prefecture | Kariya | ART | Fortified Manor | Ruins only |
| Hakii Castle | 2025 | Yamanashi Prefecture | Minobu | ART | Mountaintop | Ruins only |
| Hakii Yakata | 2025 | Yamanashi Prefecture | Minobu | ART | Fortified Manor | Ruins only |
| Hakota Castle (Kozuke) | 2021 | Gunma Prefecture | Shibukawa | ART | Mountaintop | Ruins only |
| Hakoyama Castle (Takai) | 2020 | Nagano Prefecture | Nakano | ART | Mountaintop | Ruins only |
| Hakoyanagi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Hakusan Castle | 2016 | Yamanashi Prefecture | Nirasaki | Eric | Mountaintop | Ruins only |
| Hakusan Castle (Harima) | 2017 | Hyogo Prefecture | Himeji | ART | Mountaintop | Ruins only |
| Hamada Castle | 2015 | Shimane Prefecture | Hamada | Eric | Mountaintop | No main keep but other buildings |
| Hamada Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Flatland | No main keep but other buildings |
| Hamagawa Castle | 2022 | Gunma Prefecture | Takasaki | ART | Flatland | Ruins only |
| Hamamatsu Castle | 1999 | Shizuoka Prefecture | Hamamatsu | Eric | Hilltop | Reconstructed main keep |
| Hanagoya Castle (Murakami Clan Fort Network) | 2021 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Hanakuma Castle | 2016 | Hyogo Prefecture | Kobe | ART | Flatland | Ruins only |
| Hanamaki Castle | 2018 | Iwate Prefecture | Hanamaki | ART | Hilltop | No main keep but other buildings |
| Hanaoka Castle (Azumi) | 2023 | Nagano Prefecture | Ikeda | ART | Mountaintop | Ruins only |
| Hanaoka Castle (Saku) | 2021 | Nagano Prefecture | Sakuho | ART | Mountaintop | No main keep but other buildings |
| Hanaoka Castle (Suwa) | 2019 | Nagano Prefecture | Okaya | ART | Hilltop | Ruins only |
| Hanasaki Castle (Tsuru) | 2023 | Yamanashi Prefecture | Ôtsuki | ART | Mountaintop | Ruins only |
| Hanawa Castle | 2017 | Chiba Prefecture | Nagareyama | Eric | Hilltop | Ruins only |
| Hanazawa Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Hanazono Castle | 2018 | Saitama Prefecture | Yorii | Eric | Mountaintop | Ruins only |
| Hanazono Mitake Castle | 2018 | Saitama Prefecture | Yorii | Eric | Mountaintop | Ruins only |
| Hanehigashi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Hanenishi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Haneo Castle | 2022 | Gunma Prefecture | Naganohara | ART | Mountaintop | Ruins only |
| Hannyaji Castle | 2025 | Hyogo Prefecture | Tanba Sasayama | Eric | Mountaintop | Ruins only |
| Harano Castle (Suwa) | 2023 | Nagano Prefecture | Chino | ART | Hilltop | Ruins only |
| Haranomoto Castle | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Haruyamako Castle | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Haruyamaoh Castle | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Hasedo Castle | 2012 | Yamagata Prefecture | Yamagata City | Eric | Mountaintop | Ruins only |
| Hashira Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hatada Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Fortified Manor | Ruins only |
| Hatakenaka Yakata | 2020 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Hatayama Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Hatchou Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hatsuzawa Castle | 2020 | Tokyo | Hachioji | ART | Mountaintop | Ruins only |
| Hatta Yashiki | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | No main keep but other buildings |
| Hattori Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Hilltop | Ruins only |
| Hayakawa Yashiki (Kai) | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Hayaotoshi Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Hayashi Kohee Yashiki | 2022 | Yamanashi Prefecture | Chūō | ART | Fortified Manor | Ruins only |
| Hayashikojo Castle | 2015 | Nagano Prefecture | Matsumoto | Eric | Mountaintop | Ruins only |
| Hayashiohjo Castle | 2015 | Nagano Prefecture | Matsumoto | Eric | Mountaintop | Ruins only |
| Hayashizore Castle | 2024 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Hazu Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Hilltop | Ruins only |
| Hazu Jin'ya | 2023 | Aichi Prefecture | Nishio | ART | Flatland | Ruins only |
| Hekirichi Jinya | 2011 | Hokkaido | Hokuto | RonS | Flatland | No main keep but other buildings |
| Hekitani Castle | 2024 | Kyoto | Ayabe | Eric | Mountaintop | Ruins only |
| Henmi Yashiki (Kai) | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Hida Castle (Omi) | 2022 | Shiga Prefecture | Hikone | 豪谷 | Flatland | Ruins only |
| Hieinoyama Fort | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Higashi Goma Castle | 2025 | Kyoto | Nantan | Eric | Mountaintop | Ruins only |
| Higashi Kuramae Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Higashi Maruoka Castle (Koka) | 2022 | Shiga Prefecture | Konan | Eric | Hilltop | Ruins only |
| Higashi Sakabe Castle | 2025 | Mie Prefecture | Yokkaichi | ART | Hilltop | Ruins only |
| Higashi Wada Castle | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Higashijou Castle (Chikuma) | 2021 | Nagano Prefecture | Chikuhoku | ART | Mountaintop | Ruins only |
| Higuchi Castle (Omi) | 2022 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Higuchiuchi Castle (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Hilltop | Ruins only |
| Hijika Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | No main keep but other buildings |
| Hijiyama Castle (Iga) | 2022 | Mie Prefecture | Iga | 豪谷 | Mountaintop | Ruins only |
| Hikaru Castle | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Hiki Castle | 2022 | Nagano Prefecture | Ikusaka | ART | Mountaintop | Ruins only |
| Hikida Castle | 2023 | Fukui Prefecture | Tsuruga | ART | Mountaintop | Ruins only |
| Hikidono Yashiki | 2022 | Nagano Prefecture | Ikusaka | ART | Fortified Manor | Ruins only |
| Hikobe Yashiki | 2020 | Gunma Prefecture | Kiryu | Eric | Fortified Manor | No main keep but other buildings |
| Hikone Castle | 1999 | Shiga Prefecture | Hikone | Eric | Hilltop | Original main keep |
| Hikuma Castle | 2020 | Shizuoka Prefecture | Hamamatsu | Eric | Hilltop | Ruins only |
| Hime Castle (Chikuma) | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Hime Castle (Hanishina) | 2021 | Nagano Prefecture | Sakaki | ART | Mountaintop | Ruins only |
| Hime Castle (Mikawa) | 2020 | Aichi Prefecture | Anjo | ART | Fortified Manor | Ruins only |
| Himega Castle (Mikawa) | 2022 | Aichi Prefecture | Okazaki | 豪谷 | Mountaintop | Ruins only |
| Himeji Castle | 1999 | Hyogo Prefecture | Himeji | Eric | Hilltop | Original main keep |
| Himuro Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Hina Yashiki | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hinatabata Yakata | 2023 | Nagano Prefecture | Ueda | ART | Fortified Manor | Ruins only |
| Hino Castle | 2023 | Shiga Prefecture | Hino | Furinkazan | Hilltop | Ruins only |
| Hinode Castle | 2022 | Yamanashi Prefecture | Nirasaki | ART | Hilltop | Ruins only |
| Hinohara Castle | 2023 | Tokyo | Hinohara | ART | Mountaintop | Ruins only |
| Hirabayashi Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Hirado Castle | 2011 | Nagasaki Prefecture | Hirado | Frank T. | Hilltop | Reconstructed main keep |
| Hirai Castle | 2017 | Gunma Prefecture | Fujioka | Eric | Hilltop | Ruins only |
| Hirai Castle (Omi) | 2021 | Shiga Prefecture | Aishou | ART | Fortified Manor | Ruins only |
| Hirai Kanayama Castle | 2017 | Gunma Prefecture | Fujioka | Eric | Mountaintop | Ruins only |
| Hirai Yashiki (Kai) | 2022 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Hiraide Moated Settlement | 2021 | Nagano Prefecture | Shiojiri | ART | Flatland | No main keep but other buildings |
| Hiraiwa Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hiraizumi Date | 2023 | Iwate Prefecture | Hiraizumi | Furinkazan | Fortified Manor | No main keep but other buildings |
| Hirakura Castle | 2021 | Nagano Prefecture | Otari | ART | Mountaintop | Ruins only |
| Hirao Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Hilltop | Ruins only |
| Hirase Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Hirase Kitano Castle | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Hirase Noroshidai | 2022 | Yamanashi Prefecture | Kōfu | ART | Mountaintop | Ruins only |
| Hirase Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Hirata Yashiki | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | No main keep but other buildings |
| Hiratsuka Castle | 2021 | Tokyo | Tokyo | Eric | Hilltop | Ruins only |
| Hirosaki Castle | 1999 | Aomori Prefecture | Hirosaki | Eric | Hilltop | Original main keep |
| Hirose Castle (Hida) | 2022 | Gifu Prefecture | Takayama | 豪谷 | Mountaintop | Ruins only |
| Hiroshima Castle | 1999 | Hiroshima Prefecture | Hiroshima | Eric | Flatland | Reconstructed main keep |
| Hirota Castle | 2023 | Nagano Prefecture | Nagano | ART | Flatland | No main keep but other buildings |
| Hisawa Castle | 2020 | Nagano Prefecture | Chino | ART | Mountaintop | Ruins only |
| Hishakuyama Castle | 2020 | Gunma Prefecture | Kiryu | Eric | Mountaintop | Ruins only |
| Hitomoshi Castle (Saku) | 2021 | Nagano Prefecture | Minami-Aiki | ART | Mountaintop | No main keep but other buildings |
| Hitomoshiyama Fort (Suwa) | 2023 | Nagano Prefecture | Okaya | ART | Mountaintop | Ruins only |
| Hitoyoshi Castle | 2012 | Kumamoto Prefecture | Hitoyoshi | Frank T. | Hilltop | No main keep but other buildings |
| Hiyama Castle | 2021 | Akita Prefecture | Noshiro | Eric | Mountaintop | Ruins only |
| Hizen Nagoya Castle | 2011 | Saga Prefecture | Karatsu | Kyushudan | Hilltop | Ruins only |
| Hobonishi Castle | 2025 | Mie Prefecture | Yokkaichi | ART | Hilltop | Ruins only |
| Hodarakuji Castle | 2019 | Shiga Prefecture | Koka | ART | Flatland | Ruins only |
| Hojo Clan Residence | 2021 | Shizuoka Prefecture | Izunokuni | ART | Fortified Manor | Ruins only |
| Hokkyu Castle | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | No main keep but other buildings |
| Hokkyu Jin'ya | 2024 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Hongou Castle (Owari) | 2025 | Aichi Prefecture | Nisshin | ART | Fortified Manor | Ruins only |
| Honjin'yama Castle (Mino) | 2025 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Honjinzawabata Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Honshouji Castle | 2020 | Aichi Prefecture | Anjo | ART | Flatland | No main keep but other buildings |
| Hora Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hora Yakata | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Hori Castle (Minochi) | 2023 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Horigane Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Horigoe Palace | 2021 | Shizuoka Prefecture | Izunokuni | ART | Flatland | Ruins only |
| Horikawa Castle | 2024 | Shizuoka Prefecture | Hamamatsu | ART | Flatland | Ruins only |
| Horikoshi Castle | 2021 | Aomori Prefecture | Hirosaki | Eric | Flatland | Ruins only |
| Horinouchi Castle (Kai) | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Horinouchi Yakata (Azumi) | 2022 | Nagano Prefecture | Ikeda | ART | Fortified Manor | Ruins only |
| Horinouchi Yakata (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Fortified Manor | Ruins only |
| Horinouchi Yashiki | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | No main keep but other buildings |
| Horishi Yakata (Omi) | 2025 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Horiuchi Castle (Mikawa) | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Horiuchi Shingu Castle | 2025 | Wakayama Prefecture | Shingū | ART | Fortified Manor | Ruins only |
| Hoshigasaki Castle | 2022 | Shiga Prefecture | Ryuo | Eric | Mountaintop | Ruins only |
| Hoshina Maenoyama Fort | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Hoshina Yakata | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | No main keep but other buildings |
| Hoshiyamako Castle | 2025 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Hosogaya Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Hosokawagonsui Castle | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Hosokawaonmaeda Castle | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hosokawashiroyama Castle | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Hosshouji Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Hotaka Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Hotta no Saku | 2012 | Akita Prefecture | Daisen | Frank T. | Flatland | No main keep but other buildings |
| Houjiin Doi | 2022 | Shizuoka Prefecture | Gotemba | ART | Fortified Manor | Ruins only |
| Hourinji Yakata | 2023 | Tokyo | Akiruno | ART | Fortified Manor | Ruins only |
| Houshouji Fort | 2020 | Nagano Prefecture | Saku | ART | Mountaintop | Ruins only |
| Houzouji Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Hyakusaiji Castle | 2013 | Shiga Prefecture | Higashi Omi | ART | Mountaintop | Ruins only |
| Hyogo Castle | 2020 | Hyogo Prefecture | Kobe | Andrew A | Flatland | No main keep but other buildings |
| Iba Castle | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Flatland | Ruins only |
| Iba Palace | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Flatland | Ruins only |
| Ibako Castle | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Ibaraki Castle | 2014 | Osaka | Ibaraki | Eric | Flatland | No main keep but other buildings |
| Ibarayama Castle | 2022 | Nagano Prefecture | Hakuba | ART | Mountaintop | Ruins only |
| Ibayama Castle | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Mountaintop | Ruins only |
| Ibi Castle | 2025 | Gifu Prefecture | Ibigawa | ART | Mountaintop | Ruins only |
| Ibuka Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Ichiba Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Hilltop | Ruins only |
| Ichibajin'yama Castle (Koka) | 2021 | Shiga Prefecture | Koka | ART | Fortified Manor | Ruins only |
| Ichigousan Castle | 2022 | Gunma Prefecture | Takasaki | ART | Mountaintop | Reconstructed main keep |
| Ichijodani Castle | 2013 | Fukui Prefecture | Fukui | Eric | Mountaintop | No main keep but other buildings |
| Ichijodani Kojo Castle | 2023 | Fukui Prefecture | Fukui | Eric | Mountaintop | Ruins only |
| Ichijodaniyama Castle | 2023 | Fukui Prefecture | Fukui | Eric | Mountaintop | Ruins only |
| Ichijojiyama Castle | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Ichikawa Jin'ya | 2021 | Yamanashi Prefecture | Ichikawamisato | ART | Flatland | Ruins only |
| Ichinodaira Castle (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Ichinomiya Castle | 2012 | Tokushima Prefecture | Tokushima City | RaymondW | Mountaintop | Ruins only |
| Ida Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Ide Yakata | 2023 | Shizuoka Prefecture | Fujinomiya | ART | Fortified Manor | No main keep but other buildings |
| Iden Castle | 2025 | Kyoto | Ayabe | Eric | Mountaintop | Ruins only |
| Iden Miyanokoshi Castle | 2025 | Kyoto | Ayabe | Eric | Fortified Manor | Ruins only |
| Iga Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iga Ueno Castle | 2007 | Mie Prefecture | Iga | Frank T. | Hilltop | Reconstructed main keep |
| Igawa Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Ii Yakata | 2024 | Shizuoka Prefecture | Hamamatsu | ART | Fortified Manor | Ruins only |
| Iida Castle | 2020 | Nagano Prefecture | Iida | ART | Hilltop | No main keep but other buildings |
| Iida Castle (Azumi) | 2023 | Nagano Prefecture | Hakuba | ART | Mountaintop | Ruins only |
| Iida Castle (Totomi) | 2025 | Shizuoka Prefecture | Mori | ART | Mountaintop | Ruins only |
| Iida Fort | 2020 | Nagano Prefecture | Azumino | ART | Flatland | Ruins only |
| Iida Yashiki | 2023 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Iidako Castle (Totomi) | 2025 | Shizuoka Prefecture | Mori | ART | Mountaintop | Ruins only |
| Iijima Jin'ya | 2020 | Nagano Prefecture | Iijima | ART | Flatland | No main keep but other buildings |
| Iimori Castle | 2023 | Osaka | Shijonawate | Eric | Mountaintop | Ruins only |
| Iimori Castle (Azumi) | 2023 | Nagano Prefecture | Hakuba | ART | Mountaintop | Ruins only |
| Iimoriyama Castle (Asuke) | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Iinawa Castle | 2020 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Iino Taira Castle | 2018 | Fukushima Prefecture | Iwaki | ART | Hilltop | Ruins only |
| Iinoya Castle | 2024 | Shizuoka Prefecture | Hamamatsu | ART | Mountaintop | Ruins only |
| Iinuma Castle | 2018 | Ibaraki Prefecture | Ibaraki-machi | ART | Flatland | Ruins only |
| Iiyama Castle | 2020 | Nagano Prefecture | Iiyama | ART | Hilltop | No main keep but other buildings |
| Iizuna Castle (Murakami Clan Fort Network) | 2021 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Iji Castle | 2023 | Miyagi Prefecture | Kurihara | ART | Flatland | No main keep but other buildings |
| Ijiri Yashiki | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | No main keep but other buildings |
| Ikarashi Yakata | 2023 | Niigata Prefecture | Sanjō | ART | Fortified Manor | Ruins only |
| Ikeda Castle | 2012 | Osaka | Ikeda City | Eric | Hilltop | Reconstructed main keep |
| Ikeda Castle (Mino) | 2021 | Gifu Prefecture | Tajimi | ART | Mountaintop | Ruins only |
| Ikeda Yakata (Omi) | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Fortified Manor | Ruins only |
| Ikenoshiri Yakata | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Fortified Manor | Ruins only |
| Ikkui Yashiki (Kai) | 2022 | Yamanashi Prefecture | Shōwa | ART | Fortified Manor | Ruins only |
| Ima Castle (Mino) | 2021 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Imabari Castle | 2001 | Ehime Prefecture | Imabari | Eric | Flatland | Reconstructed main keep |
| Imai Castle | 2015 | Tokyo | Oume | Eric | Hilltop | Ruins only |
| Imai Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Imai Jin'ya | 2019 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Imai Yashiki (Kai) | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Imamura Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Imamura Castle (Yamashiro) | 2020 | Kyoto | Kyoto | ART | Fortified Manor | Ruins only |
| Imasu Castle (Mino) | 2025 | Gifu Prefecture | Sekigahara | ART | Flatland | Ruins only |
| Imori Castle (Suwa) | 2020 | Nagano Prefecture | Suwa | ART | Mountaintop | Ruins only |
| Imoto Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Hilltop | Ruins only |
| Ina Castle | 2020 | Aichi Prefecture | Toyokawa | ART | Flatland | No main keep but other buildings |
| Ina Yashiki | 2022 | Saitama Prefecture | Ina | Eric | Fortified Manor | Ruins only |
| Inamura Castle (Ina) | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Inamurafuru Castle | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Inaniwa Castle | 2016 | Akita Prefecture | Yuzawa | ART | Mountaintop | Reconstructed main keep |
| Inariyama Castle (Saku) | 2021 | Nagano Prefecture | Saku | ART | Mountaintop | Ruins only |
| Inariyama Castle (Sarashina) | 2020 | Nagano Prefecture | Chikuma | ART | Flatland | Ruins only |
| Inatsuke Castle | 2015 | Tokyo | Tokyo | Eric | Hilltop | Ruins only |
| Inawashiro Castle | 2011 | Fukushima Prefecture | Inawashiro | Eric | Hilltop | Ruins only |
| Injiki Castle | 2024 | Gifu Prefecture | Hashima | ART | Flatland | Ruins only |
| Innoshima Suigun Castle | 2013 | Hiroshima Prefecture | Onomichi | Furinkazan | Hilltop | Reconstructed main keep |
| Inoko Yakata | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Inokuchi Castle | 2024 | Aichi Prefecture | Toyota | ART | Hilltop | Ruins only |
| Inokuchi Castle (Nukata) | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Inokura Castle | 2024 | Kyoto | Kameoka | Eric | Mountaintop | Ruins only |
| Inoue Castle | 2022 | Nagano Prefecture | Suzaka | ART | Mountaintop | Ruins only |
| Inoue Yakata | 2022 | Nagano Prefecture | Suzaka | ART | Fortified Manor | Ruins only |
| Inoue Yakata (Shiga) | 2023 | Shiga Prefecture | Ryuo | Eric | Fortified Manor | Ruins only |
| Inuinofuru Castle | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Inukai Castle | 2016 | Nagano Prefecture | Matsumoto | Eric | Mountaintop | Ruins only |
| Inukai Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Inuyama Castle | 1999 | Aichi Prefecture | Inuyama | Eric | Hilltop | Original main keep |
| Ioto Castle | 2022 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Iouji Fort | 2023 | Aichi Prefecture | Shinshiro | ART | Mountaintop | No main keep but other buildings |
| Ioyama Castle | 2013 | Okayama Prefecture | Tsuyama | Phibbyfan | Mountaintop | Ruins only |
| Iroganeyama Fort | 2023 | Aichi Prefecture | Nagakute | ART | Mountaintop | No main keep but other buildings |
| Isawa Castle | 2018 | Iwate Prefecture | Oushuu | ART | Flatland | Ruins only |
| Isawa Jin'ya | 2022 | Yamanashi Prefecture | Fuefuki | ART | Flatland | No main keep but other buildings |
| Isezaki Castle (Sanada) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Ishibashi Castle | 2023 | Aichi Prefecture | Shinshiro | ART | Fortified Manor | Ruins only |
| Ishibayama Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Mountaintop | Ruins only |
| Ishida Castle (Mikawa) | 2023 | Aichi Prefecture | Shinshiro | ART | Hilltop | Ruins only |
| Ishida Jin'ya | 2023 | Aichi Prefecture | Shinshiro | ART | Flatland | Ruins only |
| Ishigakiyama Ichiya Castle | 2009 | Kanagawa Prefecture | Odawara | Eric | Mountaintop | Ruins only |
| Ishigami Castle | 2018 | Ibaraki Prefecture | Toukai-mura | ART | Hilltop | Ruins only |
| Ishihama Castle | 2022 | Tokyo | Tokyo | ART | Flatland | Ruins only |
| Ishikawa Jouzan Yashiki | 2024 | Aichi Prefecture | Anjō | ART | Fortified Manor | No main keep but other buildings |
| Ishimakiyama Castle | 2025 | Aichi Prefecture | Toyohashi | ART | Mountaintop | Ruins only |
| Ishimura Castle | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Ishinomaki Castle | 2023 | Miyagi Prefecture | Ishinomaki | AnneMcL | Hilltop | Ruins only |
| Ishitono Yashiki | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Ishiwata Yakata | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Isobe Castle | 2018 | Gunma Prefecture | Annaka | Eric | Mountaintop | Ruins only |
| Isobe Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Isshiki Castle (Chita) | 2023 | Aichi Prefecture | Minami-Chita | ART | Mountaintop | No main keep but other buildings |
| Isshiki Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Flatland | Ruins only |
| Isshiki Castle (Suruga) | 2023 | Shizuoka Prefecture | Nagaizumi | ART | Hilltop | Ruins only |
| Isshindenjinai Moated Settlement | 2025 | Mie Prefecture | Tsu | ART | Flatland | No main keep but other buildings |
| Itabashi Castle | 2022 | Tokyo | Tokyo | Eric | Hilltop | Ruins only |
| Itadafuru Yashiki (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Itagaki Kanenobu Yashiki | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Itagakiyama Noroshidai | 2023 | Yamanashi Prefecture | Kōfu | ART | Mountaintop | Ruins only |
| Itami Castle | 2013 | Hyogo Prefecture | Itami | Eric | Flatland | Ruins only |
| Itazuke Moated Settlement | 2020 | Fukuoka Prefecture | Fukuoka | ART | Flatland | No main keep but other buildings |
| Itoi Jin'ya | 2021 | Hyogo Prefecture | Asago | ART | Flatland | No main keep but other buildings |
| Itoigawa Jinya | 2021 | Niigata Prefecture | Itoigawa | ART | Hilltop | Ruins only |
| Itokazu Castle | 2022 | Okinawa Prefecture | Nanjo City | RaymondW | Hilltop | Ruins only |
| Itou Genba Yashiki | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Itousakaue Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Iuchi Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwabitsu Castle | 2016 | Gunma Prefecture | Higashiazuma | Eric | Mountaintop | Ruins only |
| Iwabuchi Castle (Aida) | 2022 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Iwade Danjou Kyokan | 2020 | Gifu Prefecture | Tarui | ART | Fortified Manor | Ruins only |
| Iwade Yashiki (Kai) | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Iwadono Castle | 2011 | Yamanashi Prefecture | Otsuki | Eric | Mountaintop | No main keep but other buildings |
| Iwahara Castle (Azumi) | 2021 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Iwahori Castle (Mikawa) | 2023 | Aichi Prefecture | Kōta | ART | Fortified Manor | Ruins only |
| Iwaki Taira Castle | 2015 | Fukushima Prefecture | Iwaki | ART | Hilltop | No main keep but other buildings |
| Iwakiri Castle | 2021 | Miyagi Prefecture | Sendai | Eric | Mountaintop | Ruins only |
| Iwakubo Yakata | 2023 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Iwakuni Castle | 1999 | Yamaguchi Prefecture | Iwakuni | Eric | Mountaintop | Reconstructed main keep |
| Iwakura Castle | 2022 | Shiga Prefecture | Yasu | ART | Mountaintop | Ruins only |
| Iwakura Castle (Mikawa) | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Iwakura Castle (Owari) | 2024 | Aichi Prefecture | Iwakura | ART | Flatland | Ruins only |
| Iwakura Yakata (Mikawa) | 2024 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Iwakuratouge Castle (Mikawa) | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Iwamura Castle | 2007 | Gifu Prefecture | Ena | RaymondW | Mountaintop | No main keep but other buildings |
| Iwaoka Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Iwasaki Castle | 2008 | Aichi Prefecture | Nisshin | ART | Hilltop | Reconstructed main keep |
| Iwasaki Castle (Hanishina) | 2021 | Nagano Prefecture | Sakaki | ART | Mountaintop | Ruins only |
| Iwasaki Castle (Mutsu) | 2018 | Iwate Prefecture | Kitakami | ART | Hilltop | Ruins only |
| Iwasaki Yakata | 2022 | Yamanashi Prefecture | Kōshū | ART | Hilltop | Ruins only |
| Iwasakiyama Fort | 2025 | Shiga Prefecture | Nagahama | Eric | Mountaintop | Ruins only |
| Iwaseyama Castle | 2017 | Fukushima Prefecture | Sukagawa | ART | Mountaintop | Ruins only |
| Iwato Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwatsuki Castle | 2009 | Saitama Prefecture | Saitama City | Eric | Flatland | No main keep but other buildings |
| Iwaya Castle | 2013 | Fukuoka Prefecture | Dazaifu | ART | Mountaintop | Ruins only |
| Iwazu Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Iwazu Daizen Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwazu Daizennishi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwazu Dannoue Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwazu Ino Castle | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Iwazu Kibira Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Iwazu Myoshinji Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwazu Naruse Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Iwazushin Castle | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Iyo Matsuyama Castle | 2001 | Ehime Prefecture | Matsuyama | Eric | Hilltop | Original main keep |
| Izaki Castle | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Izu Nagahama Castle | 2016 | Shizuoka Prefecture | Numazu | Eric | Hilltop | No main keep but other buildings |
| Izuki Jin'ya | 2020 | Nagano Prefecture | Iida | ART | Hilltop | No main keep but other buildings |
| Izumi Jin'ya | 2016 | Fukushima Prefecture | Iwaki | ART | Flatland | No main keep but other buildings |
| Izumigashira Castle | 2021 | Shizuoka Prefecture | Mishima | ART | Flatland | Ruins only |
| Izushi Castle | 2004 | Hyogo Prefecture | Izushi | Eric | Hilltop | No main keep but other buildings |
| Jikki Yashiki | 2023 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Jikouin Fort | 2022 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Jikouin Yakata | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Jinbagahara Castle | 2022 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Jindaiji Castle | 2012 | Tokyo | Chofu | Eric | Hilltop | Ruins only |
| Jinguuji Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Jinnoya Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Jionji Yakata | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Jissouji Yakata | 2025 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Jizen Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Hilltop | Ruins only |
| Jofukuji Castle | 2016 | Tokyo | Hachioji | Eric | Mountaintop | Ruins only |
| Jou Ian Yashiki | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Jouguuji Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Jouhikage Fort | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Joujou Castle | 2020 | Aichi Prefecture | Kasugai | ART | Flatland | Ruins only |
| Joukouin Yakata | 2022 | Nagano Prefecture | Saku | ART | Fortified Manor | Ruins only |
| Joumineyama Castle | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Joumura Castle (Ina) | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Joumurafuru Castle | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Jounoue Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Jukkumi Yashiki | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Junhanshi Yashiki | 2023 | Fukui Prefecture | Mihama | ART | Fortified Manor | Ruins only |
| Jurakudai | 2020 | Kyoto | Kyoto | ART | Flatland | No main keep but other buildings |
| Juuouzan Fort | 2022 | Gunma Prefecture | Tomioka | ART | Mountaintop | Ruins only |
| Kabuto Castle | 2025 | Mie Prefecture | Kameyama | ART | Mountaintop | Ruins only |
| Kadone Castle (Omi) | 2022 | Shiga Prefecture | Maibara | ART | Hilltop | Ruins only |
| Kaesa Castle | 2020 | Nagano Prefecture | Nakano | ART | Mountaintop | Ruins only |
| Kagami Yakata | 2023 | Yamanashi Prefecture | Minami-Alps | ART | Fortified Manor | Ruins only |
| Kagamiyama Fort | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Kaganoi Castle | 2024 | Gifu Prefecture | Hashima | ART | Flatland | Ruins only |
| Kageyama Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Kagikakemonomi Fort | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kagohana Fort | 2025 | Shizuoka Prefecture | Shizuoka | ART | Mountaintop | Ruins only |
| Kagoshima Castle | 2013 | Kagoshima Prefecture | Kagoshima City | | Flatland | No main keep but other buildings |
| Kaguraoka Castle | 2024 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Kaibai Castle | 2020 | Nagano Prefecture | Azumino | ART | Flatland | Ruins only |
| Kaibara Jinya | 2020 | Hyogo Prefecture | Tanba | Andrew A | Flatland | No main keep but other buildings |
| Kaiden Castle | 2014 | Kyoto | Nagaoka | Eric | Fortified Manor | Ruins only |
| Kaize Castle (Saku) | 2021 | Nagano Prefecture | Sakuho | ART | Mountaintop | Ruins only |
| Kajiya Castle | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | No main keep but other buildings |
| Kake Castle (Hazu) | 2023 | Aichi Prefecture | Nishio | ART | Hilltop | Ruins only |
| Kake Castle (Nukata) | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Kakegawa Castle | 1999 | Shizuoka Prefecture | Kakegawa | Eric | Hilltop | Reconstructed main keep |
| Kakegawako Castle | 2022 | Shizuoka Prefecture | Kakegawa | ART | Mountaintop | Ruins only |
| Kakiage Castle (Chikuma) | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kakimi Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Flatland | Ruins only |
| Kakinohana Castle | 2023 | Okinawa Prefecture | Nanjo City | RaymondW | Hilltop | Ruins only |
| Kakizaki Castle | 2023 | Niigata Prefecture | Jōetsu | ART | Mountaintop | No main keep but other buildings |
| Kakuhari Yashiki | 2022 | Nagano Prefecture | Suzaka | ART | Fortified Manor | Ruins only |
| Kakunodate Castle | 1999 | Akita Prefecture | Semboku | Eric | Mountaintop | No main keep but other buildings |
| Kakutsugawa Castle | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Kamaenohaka Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Kamagari Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Kamagatake Castle | 2020 | Nagano Prefecture | Nakano | ART | Mountaintop | Ruins only |
| Kamaha Castle | 2023 | Shiga Prefecture | Maibara | Eric | Mountaintop | Ruins only |
| Kamaian Yakata | 2020 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | No main keep but other buildings |
| Kamakata Jin'ya | 2023 | Aichi Prefecture | Gamagôri | ART | Flatland | No main keep but other buildings |
| Kameda Castle | 2016 | Akita Prefecture | Yurihonjo | ART | Flatland | Reconstructed main keep |
| Kamegasaki Castle | 2023 | Yamagata Prefecture | Sakata | ART | Flatland | No main keep but other buildings |
| Kamei Castle | 2012 | Hiroshima Prefecture | Otake | Eric | Hilltop | Ruins only |
| Kamei Castle (Murakami Clan Fort Network) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Kameyama Battery | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Hilltop | Ruins only |
| Kameyama Castle | 2008 | Mie Prefecture | Kameyama | ART | Hilltop | No main keep but other buildings |
| Kameyama Castle (Azumi) | 2019 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Kameyama Castle (Kii) | 2023 | Wakayama Prefecture | Gobo | Eric | Mountaintop | Ruins only |
| Kameyama Castle (Mikawa) | 2023 | Aichi Prefecture | Shinshiro | ART | Hilltop | Ruins only |
| Kami Castle (Suwa) | 2020 | Nagano Prefecture | Shimo-Suwa | ART | Mountaintop | Ruins only |
| Kamigare Castle | 2025 | Gifu Prefecture | Ibigawa | ART | Fortified Manor | Ruins only |
| Kamigatou Yashiki | 2022 | Yamanashi Prefecture | Shōwa | ART | Fortified Manor | Ruins only |
| Kamigishimoto Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Mountaintop | Ruins only |
| Kamihiraideko Castle (Ina) | 2021 | Nagano Prefecture | Tatsuno | ART | Hilltop | Ruins only |
| Kamiiida Jin'ya | 2022 | Yamanashi Prefecture | Kōfu | ART | Flatland | Ruins only |
| Kamijima Castle (Ina) | 2022 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Kamikurabara Fort | 2023 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Kamimakifuru Castle | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Kaminagahara Castle | 2022 | Shiga Prefecture | Yasu | ART | Fortified Manor | Ruins only |
| Kaminogou Castle | 2022 | Aichi Prefecture | Gamagōri | ART | Hilltop | Ruins only |
| Kaminoyama Castle | 1999 | Yamagata Prefecture | Kaminoyama | Eric | Hilltop | Reconstructed main keep |
| Kamioka Castle | 2011 | Gifu Prefecture | Hida City | ART | Hilltop | Reconstructed main keep |
| Kamitohno Castle | 2016 | Fukushima Prefecture | Iwaki | ART | Mountaintop | Ruins only |
| Kamiwada Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Kamo Castle (Bitchu) | 2022 | Okayama Prefecture | Okayama | ART | Flatland | Ruins only |
| Kamogatake Castle | 2021 | Nagano Prefecture | Nakano | ART | Mountaintop | Ruins only |
| Kamomegasaki Battery (Obama Domain) | 2023 | Fukui Prefecture | Tsuruga | ART | Mountaintop | Ruins only |
| Kan'onsaka Castle (Hanishina) | 2022 | Nagano Prefecture | Sakaki | ART | Fortified Manor | Ruins only |
| Kanaiyama Castle | 2017 | Nagano Prefecture | Nagano | Eric | Mountaintop | Ruins only |
| Kanao Yogaisan Castle | 2018 | Saitama Prefecture | Yorii | Eric | Mountaintop | Ruins only |
| Kanasashi Yakata | 2023 | Nagano Prefecture | Shimo-Suwa | ART | Fortified Manor | Ruins only |
| Kanayama Castle | 2007 | Gunma Prefecture | Ota | Eric | Mountaintop | Ruins only |
| Kanayama Castle (Echigo) | 2021 | Niigata Prefecture | Itoigawa | ART | Mountaintop | Ruins only |
| Kanazawa Castle | 2006 | Ishikawa Prefecture | Kanazawa | Eric | Hilltop | No main keep but other buildings |
| Kanbara Castle | 2022 | Gunma Prefecture | Tsumagoi | ART | Mountaintop | Ruins only |
| Kanbayashi Castle | 2024 | Kyoto | Ayabe | Eric | Mountaintop | Ruins only |
| Kanbe Castle | 2017 | Mie Prefecture | Suzuka | ART | Flatland | No main keep but other buildings |
| Kanegasaki Battery (Obama Domain) | 2023 | Fukui Prefecture | Tsuruga | ART | Flatland | Ruins only |
| Kanegasaki Castle | 2015 | Fukui Prefecture | Tsuruga | ART | Mountaintop | Ruins only |
| Kanegasaki Castle (Iwate) | 2018 | Iwate Prefecture | Kanegasaki | Eric | Flatland | Ruins only |
| Kaneko Castle (Suwa) | 2020 | Nagano Prefecture | Suwa | ART | Flatland | Ruins only |
| Kaneko Yashiki (Minochi) | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Kanemaru Yakata | 2023 | Yamanashi Prefecture | Minami-Alps | ART | Fortified Manor | Ruins only |
| Kaneyama Castle (Mino) | 2021 | Gifu Prefecture | Kani | ART | Mountaintop | No main keep but other buildings |
| Kaneyama Castle (Mutsu) | 2017 | Miyagi Prefecture | Marumori | ART | Mountaintop | Ruins only |
| Kanmuriyama Castle (Bitchu) | 2022 | Okayama Prefecture | Okayama | ART | Mountaintop | Ruins only |
| Kannonji Castle | 2007 | Shiga Prefecture | Azuchi | Eric | Mountaintop | Ruins only |
| Kannosan Castle | 2024 | Kyoto | Kameoka | Eric | Mountaintop | Ruins only |
| Kano Castle | 2020 | Gifu Prefecture | Gifu | Eric | Flatland | Ruins only |
| Kanzeyamachi Battery (Obama Domain) | 2023 | Fukui Prefecture | Tsuruga | ART | Flatland | Ruins only |
| Kanzou Yashiki | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | No main keep but other buildings |
| Karakai Castle | 2017 | Tokyo | Oume | Eric | Mountaintop | Ruins only |
| Karasaki Castle | 2020 | Nagano Prefecture | Chikuma | ART | Mountaintop | Ruins only |
| Karasawayama Castle | 2007 | Tochigi Prefecture | Sano | Eric | Mountaintop | Ruins only |
| Karasuyama Castle | 2015 | Tochigi Prefecture | Nasu Karasuyama | Eric | Mountaintop | Ruins only |
| Karatoriya Castle | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Karatsu Castle | 2006 | Saga Prefecture | Karatsu | | Hilltop | Reconstructed main keep |
| Karidako Castle | 2022 | Nagano Prefecture | Obuse | ART | Mountaintop | Ruins only |
| Karidaoh Castle | 2022 | Nagano Prefecture | Obuse | ART | Mountaintop | Ruins only |
| Kariya Castle | 2020 | Aichi Prefecture | Kariya | ART | Hilltop | Ruins only |
| Kariyahara Castle | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kasama Castle | 2011 | Ibaraki Prefecture | Kasama | Eric | Mountaintop | No main keep but other buildings |
| Kasane Castle | 2019 | Nagano Prefecture | Asahi | ART | Mountaintop | Ruins only |
| Kasashima Castle | 2014 | Kagawa Prefecture | Marugame | | Hilltop | Ruins only |
| Kaseyama Castle | 2012 | Kyoto | Kizugawa | RaymondW | Mountaintop | Ruins only |
| Kashima Castle (Hizen) | 2020 | Saga Prefecture | Kashima | ART | Flatland | No main keep but other buildings |
| Kashiwabara Castle (Omi) | 2021 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Kashiwabara Palace | 2021 | Shiga Prefecture | Maibara | ART | Flatland | Ruins only |
| Kashiwara Castle | 2016 | Mie Prefecture | Akame | ART | Hilltop | Ruins only |
| Kashiwayama Castle (Murakami Clan Fort Network) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Kasuga Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Kasugayama Castle | 2011 | Niigata Prefecture | Joetsu | Eric | Mountaintop | No main keep but other buildings |
| Kasumi Castle | 2016 | Nagano Prefecture | Nagano | Eric | Mountaintop | Ruins only |
| Kasumiga Castle (Suwa) | 2020 | Nagano Prefecture | Shimo-Suwa | ART | Fortified Manor | Ruins only |
| Katahara Castle (Mikawa) | 2023 | Aichi Prefecture | Gamagôri | ART | Hilltop | Ruins only |
| Katakari Castle (Tanba) | 2021 | Hyogo Prefecture | Tanba | ART | Fortified Manor | Ruins only |
| Katakura Castle | 2015 | Tokyo | Hachioji | Eric | Hilltop | Ruins only |
| Katsumata Castle | 2024 | Shizuoka Prefecture | Makinohara | ART | Mountaintop | Ruins only |
| Katsumoto Castle | 2020 | Nagasaki Prefecture | Iki | Chottomat | Hilltop | Ruins only |
| Katsunuma Castle | 2015 | Tokyo | Oume | Eric | Mountaintop | Ruins only |
| Katsunumashi Yakata | 2017 | Yamanashi Prefecture | Koshu | Eric | Fortified Manor | Ruins only |
| Katsurao Castle (Hanishina) | 2021 | Nagano Prefecture | Sakaki | ART | Mountaintop | Ruins only |
| Katsurayama Castle | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Katsuren Castle | 2008 | Okinawa Prefecture | Uruma | TerryP | Mountaintop | Ruins only |
| Katsushima Castle (Omi) | 2020 | Shiga Prefecture | Aishou | ART | Flatland | Ruins only |
| Katsuyama Castle (Echigo) | 2021 | Niigata Prefecture | Itoigawa | ART | Mountaintop | Ruins only |
| Katsuyama Castle (Nagato) | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Mountaintop | Ruins only |
| Katsuyama Castle (Tsuru) | 2020 | Yamanashi Prefecture | Tsuru | Eric | Mountaintop | Ruins only |
| Katsuyama Castle (Yatsushiro) | 2022 | Yamanashi Prefecture | Kōfu | ART | Hilltop | Ruins only |
| Katsuyama Palace | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Flatland | No main keep but other buildings |
| Kattori Castle (Chikuma) | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Kawagoe Castle | 2006 | Saitama Prefecture | Kawagoe | Eric | Flatland | No main keep but other buildings |
| Kawahara Castle | 2017 | Tottori Prefecture | Tottori | ART | Hilltop | Reconstructed main keep |
| Kawajiri Castle | 2023 | Aichi Prefecture | Shinshiro | ART | Mountaintop | Ruins only |
| Kawamura Castle | 2014 | Kanagawa Prefecture | Yamakita | Eric | Mountaintop | Ruins only |
| Kawamura Yakata | 2022 | Kanagawa Prefecture | Yamakita | ART | Fortified Manor | Ruins only |
| Kawanami Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Kawanoe Castle | 2011 | Ehime Prefecture | Kawanoe | Frank T. | Mountaintop | Reconstructed main keep |
| Kawasaki Battery (Obama Domain) | 2023 | Fukui Prefecture | Obama | ART | Flatland | Ruins only |
| Kawasaki Shoujirou Yakata | 2022 | Tokyo | Tokyo | ART | Fortified Manor | Ruins only |
| Kawasaki no Saku | 2023 | Iwate Prefecture | Ichinoseki | ART | Flatland | No main keep but other buildings |
| Kawashima Castle | 2013 | Tokushima Prefecture | Yoshinogawa | RaymondW | Hilltop | Reconstructed main keep |
| Kawashimamurako Castle | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Kawawada Castle | 2018 | Ibaraki Prefecture | Mito | ART | Flatland | Ruins only |
| Kaya Yakata | 2022 | Okayama Prefecture | Okayama | ART | Fortified Manor | Ruins only |
| Kazama Yakata | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Kazama Yashiki (Kai) | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Kazue Yashiki (Nukata) | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Kazurayama Castle | 2014 | Shizuoka Prefecture | Susono | Eric | Mountaintop | Ruins only |
| Kazurayama Yakata | 2023 | Shizuoka Prefecture | Susono | Eric | Fortified Manor | Ruins only |
| Keirozan Castle | 2023 | Hyogo Prefecture | Tatsuno | Eric | Mountaintop | Ruins only |
| Kemi Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Kemi Castle (Chikuma) | 2021 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Kemurino Castle (Murakami Clan Fort Network) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Ken Castle (Kozuke) | 2021 | Gunma Prefecture | Shibukawa | ART | Fortified Manor | Ruins only |
| Kesadaira Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Kibune Castle | 2021 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Kibyu Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Kido Castle (Mikawa) | 2025 | Aichi Prefecture | Anjo | ART | Flatland | Ruins only |
| Kidoko Castle (Mikawa) | 2025 | Aichi Prefecture | Anjo | ART | Fortified Manor | Ruins only |
| Kiga Jin'ya | 2024 | Shizuoka Prefecture | Hamamatsu | ART | Hilltop | Ruins only |
| Kikkawa Motoharu Yakata | 2020 | Hiroshima Prefecture | Kita-Hiroshima | ART | Fortified Manor | No main keep but other buildings |
| Kikuchi Castle | 2009 | Kumamoto Prefecture | Yamaga | Kyushudan | Mountaintop | No main keep but other buildings |
| Kimura Castle | 2023 | Shiga Prefecture | Azuchi | Eric | Flatland | Ruins only |
| Kinebuchi Yakata | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Kinojo | 2011 | Okayama Prefecture | Soja | Eric | Mountaintop | No main keep but other buildings |
| Kinoshita Castle | 2023 | Aichi Prefecture | Inuyama | ART | Flatland | Ruins only |
| Kinowa Castle | 2023 | Yamagata Prefecture | Sakata | ART | Flatland | No main keep but other buildings |
| Kinzan Castle | 2025 | Hyogo Prefecture | Tanba Sasayama | Eric | Mountaintop | Ruins only |
| Kirarazaka Castle | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Kiridohshi Jin'ya | 2024 | Gifu Prefecture | Gifu | ART | Fortified Manor | Ruins only |
| Kiridouzan Noroshidai | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Kirihara Castle | 2016 | Nagano Prefecture | Matsumoto | Eric | Mountaintop | Ruins only |
| Kirihara Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Kirihara Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Kiriyama Castle | 2024 | Mie Prefecture | Tsu | Andrew A | Mountaintop | Ruins only |
| Kisai Castle | 2011 | Saitama Prefecture | Kazo | ART | Flatland | Reconstructed main keep |
| Kishiwada Castle | 2006 | Osaka | Kishiwada | Eric | Flatland | Reconstructed main keep |
| Kiso Daikansho | 2020 | Nagano Prefecture | Kiso | ART | Flatland | No main keep but other buildings |
| Kiso Yoshinaka Yakata | 2020 | Nagano Prefecture | Kiso | ART | Fortified Manor | Ruins only |
| Kisotono Yashiki | 2021 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Kissatsu Castle | 2024 | Yamanashi Prefecture | Yamanashi | ART | Mountaintop | Ruins only |
| Kita Kumai Castle | 2019 | Nagano Prefecture | Shiojiri | ART | Flatland | Ruins only |
| Kita Majino Castle | 2020 | Nagano Prefecture | Suwa | ART | Fortified Manor | Ruins only |
| Kita Tsuda Castle | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Mountaintop | Ruins only |
| Kita Wakamiko Castle | 2022 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Kitaaranami Fort | 2022 | Gunma Prefecture | Takasaki | ART | Flatland | No main keep but other buildings |
| Kitabatakeshi Yakata | 2020 | Mie Prefecture | Tsu | Andrew A | Fortified Manor | Ruins only |
| Kitabatakeshi Yakata Tsumenoshiro | 2025 | Mie Prefecture | Tsu | Andrew A | Mountaintop | Ruins only |
| Kitabodaiji Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Fortified Manor | Ruins only |
| Kitagata Castle (Ibi) | 2021 | Gifu Prefecture | Ibigawa | ART | Mountaintop | Ruins only |
| Kitagata Castle (Motosu) | 2025 | Gifu Prefecture | Kitagata | ART | Flatland | Ruins only |
| Kitagata Jin'ya | 2025 | Gifu Prefecture | Kitagata | ART | Flatland | Ruins only |
| Kitagejou Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Kitagejou Yashiki | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Kitamura Castle (Omi) | 2022 | Shiga Prefecture | Yasu | ART | Flatland | No main keep but other buildings |
| Kitano Castle (Ina) | 2020 | Nagano Prefecture | Miyada | ART | Hilltop | Ruins only |
| Kitanosho Castle | 2006 | Fukui Prefecture | Fukui City | Eric | Flatland | Ruins only |
| Kitanosho Castle (Omi) | 2022 | Shiga Prefecture | Omi-Hachiman | ART | Mountaintop | Ruins only |
| Kitasudayama Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Mountaintop | Ruins only |
| Kitatsumeno Fort | 2022 | Gunma Prefecture | Takasaki | ART | Flatland | Ruins only |
| Kitsuki Castle | 2011 | Oita Prefecture | Kitsuki | Frank T. | Hilltop | Reconstructed main keep |
| Kitsune Castle (Azumi) | 2020 | Nagano Prefecture | Azumino | ART | Hilltop | Ruins only |
| Kitsuneyashiki Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Kiyomizu Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Kiyosaki Castle (Echigo) | 2021 | Niigata Prefecture | Itoigawa | ART | Flatland | Ruins only |
| Kiyosu Castle | 1999 | Aichi Prefecture | Kiyosu | Eric | Flatland | Reconstructed main keep |
| Kizu Castle | 2024 | Kyoto | Kizugawa | Eric | Mountaintop | Ruins only |
| Kobinata Oh'yashiki | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Kobushi Castle (Tsuru) | 2023 | Yamanashi Prefecture | Uenohara | ART | Mountaintop | Ruins only |
| Kochi Castle | 2001 | Kochi Prefecture | Kochi | Eric | Hilltop | Original main keep |
| Kodera Castle (Mino) | 2025 | Gifu Prefecture | Ikeda | ART | Mountaintop | Ruins only |
| Kofu Castle | 2003 | Yamanashi Prefecture | Kofu | Eric | Hilltop | No main keep but other buildings |
| Koga Castle | 2022 | Ibaraki Prefecture | Koga | Furinkazan | Flatland | Ruins only |
| Kogamine Castle (Kyoto) | 2024 | Kyoto | Ayabe | Eric | Mountaintop | Ruins only |
| Kogane Castle | 2015 | Chiba Prefecture | Matsudo | Eric | Hilltop | Ruins only |
| Kogane Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Kohyama Castle | 2024 | Hyogo Prefecture | Tatsuno | Eric | Mountaintop | Ruins only |
| Koibuchi Castle | 2018 | Ibaraki Prefecture | Mito | ART | Flatland | Ruins only |
| Koide Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Koide Yakata (Tanba) | 2024 | Kyoto | Nantan | Eric | Fortified Manor | Ruins only |
| Koike Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Koiwatake Castle | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | No main keep but other buildings |
| Kojima Castle (Hida) | 2019 | Gifu Prefecture | Hida | ART | Mountaintop | Ruins only |
| Kokokuji Castle | 2014 | Shizuoka Prefecture | Numazu | Eric | Hilltop | Ruins only |
| Kokura Castle | 2006 | Fukuoka Prefecture | Kitakyushu | ART | Flatland | Reconstructed main keep |
| Kokururi Castle | 2021 | Chiba Prefecture | Kimitsu | Eric | Mountaintop | Ruins only |
| Kokuryou Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Kokuryou Castle (Tanba) | 2021 | Hyogo Prefecture | Tanba | ART | Fortified Manor | Ruins only |
| Kokuzousan Castle (Aida) | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kokuzousan Castle (Murakami Clan Fort Network) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Kokuzousan Noroshidai | 2021 | Nagano Prefecture | Saku | ART | Mountaintop | No main keep but other buildings |
| Kokuzousanminami Fort (Aida) | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kokuzousannanseioneno Castle (Aida) | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kokuzousannishi Fort (Aida) | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Komai Yashiki | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | No main keep but other buildings |
| Komaki Castle | 1999 | Aichi Prefecture | Komaki | Eric | Mountaintop | Reconstructed main keep |
| Komaki Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Komakijou Ohte Fort | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Komakikamino Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Komaruyama Castle (Kiso) | 2020 | Nagano Prefecture | Kiso | ART | Mountaintop | Ruins only |
| Komaruyama Fort (Murakami Clan Fort Network) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Komasawa Castle | 2022 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Komatsu Castle | 2019 | Ishikawa Prefecture | Komatsu | ART | Flatland | No main keep but other buildings |
| Komatsu Castle (Sagami) | 2023 | Kanagawa Prefecture | Sagamihara | ART | Mountaintop | Ruins only |
| Komatsuyama Noroshidai | 2023 | Yamanashi Prefecture | Kōfu | ART | Mountaintop | Ruins only |
| Komazawa Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Komesu Castle | 2023 | Okinawa Prefecture | Itoman City | RaymondW | Hilltop | Ruins only |
| Komihanachi Castle | 2023 | Fukui Prefecture | Fukui | Eric | Mountaintop | Ruins only |
| Komiyama Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Komono Castle | 2022 | Mie Prefecture | Komono | 豪谷 | Flatland | No main keep but other buildings |
| Komori Castle (Omi) | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Flatland | Ruins only |
| Komori Yakata (Sarashina) | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Komoro Castle | 2008 | Nagano Prefecture | Komoro | Eric | Hilltop | No main keep but other buildings |
| Kongouji Castle (Murakami Clan Fort Network) | 2022 | Nagano Prefecture | Ueda | ART | Flatland | Ruins only |
| Kongouji Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Konishi Castle (Ina) | 2020 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Konodai Castle | 2021 | Chiba Prefecture | Ichikawa | Eric | Hilltop | Ruins only |
| Konosumiyama Castle | 2013 | Hyogo Prefecture | Toyooka | Eric | Mountaintop | Ruins only |
| Koori Nishiyama Castle | 2021 | Fukushima Prefecture | Koori | Eric | Mountaintop | Ruins only |
| Koraku Castle | 2022 | Nagano Prefecture | Sakaki | ART | Mountaintop | Ruins only |
| Korin Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Mountaintop | Ruins only |
| Koriyama Castle (Hiroshima) | 2019 | Hiroshima Prefecture | Akitakata | Eric | Mountaintop | Ruins only |
| Koromo Castle | 2019 | Aichi Prefecture | Toyota | ART | Hilltop | No main keep but other buildings |
| Koromogawa Date | 2023 | Iwate Prefecture | Hiraizumi | ART | Fortified Manor | Reconstructed main keep |
| Kosakajinja Yakata | 2022 | Nagano Prefecture | Suzaka | ART | Fortified Manor | Ruins only |
| Kose Yashiki (Kai) | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Kosema Castle | 2023 | Aichi Prefecture | Toyota | ART | Mountaintop | No main keep but other buildings |
| Koshibami Castle | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Koshigoe Castle | 2015 | Saitama Prefecture | Ogawamachi | Eric | Mountaintop | Ruins only |
| Koshikou Castle (Chikuma) | 2021 | Nagano Prefecture | Chikuhoku | ART | Mountaintop | Ruins only |
| Kosobu Yakata | 2022 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Kosodeonzakijinja Castle | 2022 | Yamanashi Prefecture | Hokuto | ART | Flatland | Ruins only |
| Kosuge Castle | 2023 | Yamanashi Prefecture | Kosuge | ART | Mountaintop | Ruins only |
| Kosugeyama Yakata | 2023 | Nagano Prefecture | Ômachi | ART | Fortified Manor | Ruins only |
| Koteshiro Fort | 2025 | Yamanashi Prefecture | Fuefuki | ART | Mountaintop | Ruins only |
| Kotsukuri Castle | 2024 | Mie Prefecture | Tsu | ART | Flatland | Ruins only |
| Kotsukuriko Castle | 2024 | Mie Prefecture | Tsu | ART | Hilltop | Ruins only |
| Koudaiji Fort | 2023 | Yamanashi Prefecture | Nirasaki | ART | Flatland | Ruins only |
| Kouji Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Koujin'o Castle | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Koujin'yama Castle (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Koujin'yama Noroshidai | 2022 | Yamanashi Prefecture | Yamanashi | ART | Mountaintop | Ruins only |
| Kouka Saburo Yashiki | 2023 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Koumyo Castle | 2025 | Shizuoka Prefecture | Hamamatsu | ART | Mountaintop | Ruins only |
| Koumyoji Yakata | 2020 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Kouno Yashiki (Kai) | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Kounomine Castle | 2012 | Yamaguchi Prefecture | Yamaguchi City | ART | Mountaintop | Ruins only |
| Kounoshou Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Kouriki Castle (Mikawa) | 2023 | Aichi Prefecture | Kōta | ART | Fortified Manor | Ruins only |
| Kouyama Castle (Bingo) | 2020 | Hiroshima Prefecture | Shobara | ART | Mountaintop | Ruins only |
| Kouyama Castle (Nagato) | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Mountaintop | Ruins only |
| Koya Castle | 2022 | Nagano Prefecture | Ikusaka | ART | Mountaintop | Ruins only |
| Koya Castle (Chikuma) | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Koyaba Castle | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Koyama Castle | 2011 | Shizuoka Prefecture | Yoshida | Eric | Hilltop | Reconstructed main keep |
| Koyama Castle (Kai) | 2022 | Yamanashi Prefecture | Fuefuki | ART | Hilltop | Ruins only |
| Koyamura Yashiki | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Kozubeta Castle | 2024 | Mie Prefecture | Tsu | ART | Mountaintop | Ruins only |
| Kozukue Castle | 2010 | Kanagawa Prefecture | Yokohama | Eric | Hilltop | Ruins only |
| Kozutsumi Castle | 2022 | Shiga Prefecture | Yasu | ART | Mountaintop | Ruins only |
| Kubo Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | No main keep but other buildings |
| Kubodera Castle | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Kubodono Yashiki | 2022 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Kuboe Castle (Omi) | 2022 | Shiga Prefecture | Ôtsu | ART | Mountaintop | Ruins only |
| Kubota Castle | 2011 | Akita Prefecture | Akita City | Frank T. | Hilltop | No main keep but other buildings |
| Kubota Castle (Nukata) | 2023 | Aichi Prefecture | Kōta | ART | Fortified Manor | Ruins only |
| Kuboyashiki (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Fortified Manor | Ruins only |
| Kuboyashikishi Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Kugo Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Kukuri Castle | 2021 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Kukyudaira Castle (Mikawa) | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Kuma Castle | 2017 | Yamanashi Prefecture | Kofu | Eric | Mountaintop | Ruins only |
| Kumagawa Castle | 2025 | Fukui Prefecture | Wakasa | Eric | Mountaintop | Ruins only |
| Kumagawa Jinya | 2025 | Fukui Prefecture | Wakasa | Eric | Flatland | Ruins only |
| Kumagura Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Kumamoto Castle | 2005 | Kumamoto Prefecture | Kumamoto | Eric | Hilltop | Reconstructed main keep |
| Kunaishoyu Castle | 2022 | Kyoto | Kyoto | Eric | Fortified Manor | Ruins only |
| Kuniyoshi Castle | 2023 | Fukui Prefecture | Mihama | ART | Mountaintop | Ruins only |
| Kuno Castle | 2024 | Shizuoka Prefecture | Fukuroi | ART | Hilltop | Ruins only |
| Kunohe Castle | 2010 | Iwate Prefecture | Ninohe | Eric | Hilltop | Ruins only |
| Kunori Yakata | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Kunou Castle | 2021 | Shizuoka Prefecture | Shizuoka | ART | Mountaintop | Ruins only |
| Kurahone Castle | 2021 | Nagano Prefecture | Chikuma | ART | Mountaintop | Ruins only |
| Kuraji Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Hilltop | Ruins only |
| Kuranomae Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | No main keep but other buildings |
| Kurata Castle (Ina) | 2020 | Nagano Prefecture | Minami-Minowa | ART | Hilltop | Ruins only |
| Kurihara Yakata | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Kurita Castle | 2020 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Kuriyagawa no Saku | 2023 | Iwate Prefecture | Morioka | ART | Flatland | No main keep but other buildings |
| Kurobane Castle | 2018 | Tochigi Prefecture | Ohtawara | ART | Mountaintop | No main keep but other buildings |
| Kuroda Daikansho | 2024 | Shizuoka Prefecture | Kikugawa | ART | Flatland | No main keep but other buildings |
| Kuroi Castle | 2020 | Hyogo Prefecture | Tanba | Andrew A | Mountaintop | No main keep but other buildings |
| Kurokawashi Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Kurono Castle | 2021 | Gifu Prefecture | Gifu | ART | Flatland | Ruins only |
| Kuruma Castle | 2021 | Nagano Prefecture | Otari | ART | Mountaintop | Ruins only |
| Kuruma Castle (Hanishina) | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Kurumayama Castle (Hanishina) | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Kurume Castle | 2013 | Fukuoka Prefecture | Kurume | ART | Hilltop | Ruins only |
| Kururi Castle | 2005 | Chiba Prefecture | Kimitsu City | Eric | Mountaintop | Reconstructed main keep |
| Kusama Bizennokami Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Kushiki Castle (Chikuma) | 2020 | Nagano Prefecture | Matsumoto | ART | Flatland | Ruins only |
| Kushima Castle | 2009 | Nagasaki Prefecture | Omura | Kyushudan | Hilltop | No main keep but other buildings |
| Kushizaki Castle | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Hilltop | Ruins only |
| Kutsukake Castle | 2020 | Aichi Prefecture | Toyoake | Eric | Flatland | Ruins only |
| Kutsukakemura Fort | 2023 | Aichi Prefecture | Toyoake | ART | Flatland | Ruins only |
| Kutsuki Izuminokami Jin'ya | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Flatland | Ruins only |
| Kutsuki Shuzen Jin'ya | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Flatland | Ruins only |
| Kuwabara Castle | 2007 | Nagano Prefecture | Suwa | Eric | Mountaintop | Ruins only |
| Kuwagatahara Noroshidai | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Kuwai Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Kuwana Castle | 2013 | Mie Prefecture | Kuwana | RaymondW | Flatland | No main keep but other buildings |
| Kyara Palace | 2023 | Iwate Prefecture | Hiraizumi | ART | Fortified Manor | No main keep but other buildings |
| Kyotoshin Castle | 2020 | Kyoto | Kyoto | ART | Flatland | Ruins only |
| Kyouraishi Yashiki | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Kyouraishiminbu Yakata | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Machimura Fort | 2021 | Nagano Prefecture | Shiojiri | ART | Hilltop | Ruins only |
| Machita Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Maebashi Castle | 2016 | Gunma Prefecture | Maebashi | Eric | Flatland | Ruins only |
| Maeda Battery | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Hilltop | Ruins only |
| Maenoyama Noroshidai | 2025 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Magaribuchi Yashiki | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Magome Castle | 2019 | Gifu Prefecture | Nakatsugawa | ART | Mountaintop | Ruins only |
| Majino Castle (Kai) | 2025 | Yamanashi Prefecture | Nanbu | ART | Mountaintop | Ruins only |
| Majinooyashiki Yakata | 2023 | Nagano Prefecture | Suwa | ART | Fortified Manor | Ruins only |
| Makabe Castle | 2021 | Ibaraki Prefecture | Sakuragawa | Eric | Flatland | Ruins only |
| Makabe Jinya | 2021 | Ibaraki Prefecture | Sakuragawa | Eric | Flatland | Ruins only |
| Makino Castle (Mikawa) | 2023 | Aichi Prefecture | Toyokawa | ART | Flatland | Ruins only |
| Makita Castle (Ise) | 2024 | Mie Prefecture | Yokkaichi | ART | Fortified Manor | Ruins only |
| Mamabe Castle | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Mamushizuka Castle | 2024 | Shizuoka Prefecture | Fukuroi | ART | Hilltop | Ruins only |
| Mamyoda Fort | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Manago Castle | 2020 | Tochigi Prefecture | Tochigi | Eric | Mountaintop | Ruins only |
| Mariko Castle | 2011 | Shizuoka Prefecture | Shizuoka | Eric | Mountaintop | Ruins only |
| Marikoyama Fort | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Marugame Castle | 2005 | Kagawa Prefecture | Marugame | | Hilltop | Original main keep |
| Marune Castle | 2023 | Aichi Prefecture | Toyota | ART | Hilltop | Ruins only |
| Marune Fort | 2020 | Aichi Prefecture | Nagoya | Eric | Mountaintop | Ruins only |
| Maruoka Castle | 2006 | Fukui Prefecture | Sakai | Eric | Hilltop | Original main keep |
| Maruoka Castle (Koka) | 2022 | Shiga Prefecture | Konan | Eric | Hilltop | Ruins only |
| Maruoka Castle (Uzen) | 2023 | Yamagata Prefecture | Tsuruoka | ART | Fortified Manor | Ruins only |
| Maruyama Castle (Ina) | 2022 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Maruyama Douen Castle | 2023 | Aichi Prefecture | Okazaki | ART | Flatland | Ruins only |
| Maruyama Fort (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Maruyama Fort (Kai) | 2022 | Yamanashi Prefecture | Nirasaki | ART | Hilltop | Ruins only |
| Maruyama Mandaira Yakata | 2022 | Nagano Prefecture | Ikusaka | ART | Fortified Manor | Ruins only |
| Maruyama Noroshidai (Suwa) | 2022 | Nagano Prefecture | Fujimi | ART | Mountaintop | Ruins only |
| Maruyama Noutou Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Maruyama Tonomura Yakata | 2022 | Nagano Prefecture | Ikusaka | ART | Fortified Manor | Ruins only |
| Maruyama Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Masugata Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Masugata Castle (Musashi) | 2018 | Kanagawa Prefecture | Kawasaki | ART | Mountaintop | Ruins only |
| Masugata Castle (Suwa) | 2023 | Nagano Prefecture | Chino | ART | Hilltop | Ruins only |
| Masugata Castle (Takai) | 2023 | Nagano Prefecture | Takayama | ART | Mountaintop | Ruins only |
| Masugatayama Castle | 2017 | Tokyo | Oume | Eric | Mountaintop | Ruins only |
| Masujima Castle | 2017 | Gifu Prefecture | Hida | ART | Hilltop | Ruins only |
| Masuo Castle | 2016 | Chiba Prefecture | Kashiwa | Eric | Hilltop | Ruins only |
| Matsubara Battery (Obama Domain) | 2023 | Fukui Prefecture | Tsuruga | ART | Flatland | Ruins only |
| Matsubara Castle (Omi) | 2024 | Shiga Prefecture | Hikone | ART | Fortified Manor | No main keep but other buildings |
| Matsuda Yakata | 2020 | Nagano Prefecture | Chikuma | ART | Fortified Manor | No main keep but other buildings |
| Matsudai Castle (Echigo) | 2021 | Niigata Prefecture | Tōkamachi | ART | Mountaintop | Reconstructed main keep |
| Matsudaira Castle | 2020 | Aichi Prefecture | Toyota | Eric | Mountaintop | Ruins only |
| Matsudaira Yakata | 2020 | Aichi Prefecture | Toyota | Eric | Fortified Manor | Ruins only |
| Matsue Castle | 2004 | Shimane Prefecture | Matsue | Eric | Hilltop | Original main keep |
| Matsugasaki Castle (Yamashiro) | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Matsugashima Castle | 2024 | Mie Prefecture | Matsusaka | ART | Flatland | Ruins only |
| Matsugashita Battery (Obama Domain) | 2023 | Fukui Prefecture | Obama | ART | Flatland | Ruins only |
| Matsuho Battery | 2024 | Hyogo Prefecture | Awaji | ART | Flatland | Ruins only |
| Matsuida Castle | 2018 | Gunma Prefecture | Annaka | Eric | Mountaintop | Ruins only |
| Matsukura Castle | 2019 | Gifu Prefecture | Takayama | ART | Mountaintop | Ruins only |
| Matsumae Castle | 2006 | Hokkaido | Matsumae | VicA | Flatland | Reconstructed main keep |
| Matsumoto Castle | 1999 | Nagano Prefecture | Matsumoto | Eric | Flatland | Original main keep |
| Matsumoto Castle (Ise) | 2025 | Mie Prefecture | Yokkaichi | ART | Mountaintop | Ruins only |
| Matsuo Castle | 2016 | Nagano Prefecture | Ueda | Eric | Mountaintop | Ruins only |
| Matsuo Castle (Ina) | 2020 | Nagano Prefecture | Iida | ART | Hilltop | Ruins only |
| Matsuoyama Castle | 2022 | Gifu Prefecture | Sekigahara | ART | Mountaintop | Ruins only |
| Matsusaka Castle | 2010 | Mie Prefecture | Matsusaka | Eric | Hilltop | No main keep but other buildings |
| Matsushima Castle (Ina) | 2020 | Nagano Prefecture | Minowa | ART | Hilltop | Ruins only |
| Matsushiro Castle | 2008 | Nagano Prefecture | Nagano City | Eric | Flatland | No main keep but other buildings |
| Matsuyama Castle (Gunma) | 2017 | Gunma Prefecture | Takasaki | Eric | Mountaintop | Ruins only |
| Matsuyama Castle (Saitama) | 2011 | Saitama Prefecture | Yoshimi | Eric | Hilltop | Ruins only |
| Mayamahigashi Castle | 2022 | Gunma Prefecture | Shimonita | ART | Hilltop | Ruins only |
| Meiseireijin Fort | 2020 | Nagano Prefecture | Chikuma | ART | Mountaintop | Ruins only |
| Mekada Castle | 2021 | Shiga Prefecture | Aishou | ART | Flatland | Ruins only |
| Mibu Castle | 2018 | Tochigi Prefecture | Mibu-machi | ART | Flatland | No main keep but other buildings |
| Mibuno Castle (Iga) | 2022 | Mie Prefecture | Iga | 豪谷 | Hilltop | Ruins only |
| Michibayashi Fort | 2020 | Nagano Prefecture | Tatsuno | ART | Mountaintop | Ruins only |
| Michikusa Fort | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Mie Castle | 2022 | Okinawa Prefecture | Naha City | RaymondW | Flatland | Ruins only |
| Migawa Castle (Hitachi) | 2018 | Ibaraki Prefecture | Mito | AnneMcL | Hilltop | Ruins only |
| Mihara Castle | 2007 | Hiroshima Prefecture | Mihara | Eric | Flatland | Ruins only |
| Miharu Castle | 2016 | Fukushima Prefecture | Miharu | ART | Mountaintop | No main keep but other buildings |
| Mikawa Kou Jin'ya | 2023 | Aichi Prefecture | Toyokawa | ART | Flatland | No main keep but other buildings |
| Mikazuki Jin'ya | 2024 | Hyogo Prefecture | Sayo | Eric | Flatland | No main keep but other buildings |
| Miki Castle | 2020 | Hyogo Prefecture | Miki | Andrew A | Hilltop | Ruins only |
| Mikka Castle (Minochi) | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Mikkaichiba Castle | 2022 | Nagano Prefecture | Hakuba | ART | Mountaintop | Ruins only |
| Mikkaichiba Yakata | 2022 | Nagano Prefecture | Hakuba | ART | Fortified Manor | Ruins only |
| Mikoshiyama Castle | 2024 | Shiga Prefecture | Otsu | Eric | Mountaintop | Ruins only |
| Mikumo Castle (Koka) | 2022 | Shiga Prefecture | Konan | Eric | Mountaintop | Ruins only |
| Minagawa Castle | 2015 | Tochigi Prefecture | Tochigi | Eric | Mountaintop | Ruins only |
| Minagawa Jin'ya (Totomi) | 2025 | Shizuoka Prefecture | Iwata | ART | Flatland | No main keep but other buildings |
| Minakuchi Castle | 2006 | Shiga Prefecture | Koka | Eric | Flatland | No main keep but other buildings |
| Minakuchi Okayama Castle | 2019 | Shiga Prefecture | Kōka | ART | Mountaintop | No main keep but other buildings |
| Minami Hatta Castle | 2024 | Kyoto | Nantan | Eric | Mountaintop | Ruins only |
| Minami Kumai Castle | 2019 | Nagano Prefecture | Shiojiri | ART | Hilltop | Ruins only |
| Minami Majino Castle | 2020 | Nagano Prefecture | Suwa | ART | Mountaintop | Ruins only |
| Minami Sakaide Castle | 2020 | Ibaraki Prefecture | Naka | ART | Hilltop | Ruins only |
| Minami Tsuda Castle | 2022 | Shiga Prefecture | Ōmi-Hachiman | ART | Mountaintop | Ruins only |
| Minami Wakamiko Castle | 2022 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Minamiohshio Castle (Suwa) | 2023 | Nagano Prefecture | Chino | ART | Hilltop | Ruins only |
| Minamoto Yoshikiyo Yakata | 2022 | Yamanashi Prefecture | Shōwa | ART | Fortified Manor | Ruins only |
| Minamoto no Tsunemoto Yakata | 2020 | Saitama Prefecture | Konosu | Eric | Fortified Manor | Ruins only |
| Minato Castle | 2018 | Akita Prefecture | Akita City | Eric | Flatland | Ruins only |
| Minebata Castle | 2020 | Nagano Prefecture | Okaya | ART | Hilltop | Ruins only |
| Minegadou Castle | 2022 | Kyoto | Kyoto | ART | Mountaintop | Ruins only |
| Minokubi Castle | 2017 | Miyagi Prefecture | Yamamoto Town | ART | Hilltop | No main keep but other buildings |
| Minowa Castle | 2008 | Gunma Prefecture | Takasaki | Eric | Hilltop | No main keep but other buildings |
| Minowa Castle (Ina) | 2020 | Nagano Prefecture | Minowa | ART | Hilltop | Ruins only |
| Minton Castle | 2023 | Okinawa Prefecture | Nanjo City | RaymondW | Hilltop | Ruins only |
| Misaka Castle | 2024 | Yamanashi Prefecture | Fuefuki | ART | Mountaintop | Ruins only |
| Misaki Castle (Kuwana) | 2024 | Mie Prefecture | Kuwana | ART | Flatland | No main keep but other buildings |
| Misayama Castle | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Misonoko Castle | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Mitake Castle (Kai) | 2024 | Yamanashi Prefecture | Kōfu | ART | Mountaintop | Ruins only |
| Mito Castle | 2008 | Ibaraki Prefecture | Mito | Eric | Hilltop | No main keep but other buildings |
| Mitobe Yashiki | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Mitsugi Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Mitsui Ichibee Yashiki | 2022 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Mitsui Ukonnojou Yashiki | 2022 | Yamanashi Prefecture | Chūō | ART | Fortified Manor | Ruins only |
| Miyachi Yashiki | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Miyachifuru Yashiki | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Miyahara Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Miyaishi Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Miyanoue Castle (Saku) | 2021 | Nagano Prefecture | Kōmi | ART | Mountaintop | Ruins only |
| Miyao Castle | 2019 | Hiroshima Prefecture | Hatsukaichi | Furinkazan | Hilltop | Ruins only |
| Miyashita Yakata | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Mizuban Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Mizukami Mondo Yashiki | 2023 | Yamanashi Prefecture | Nirasaki | ART | Fortified Manor | Ruins only |
| Mizuki | 2020 | Fukuoka Prefecture | Dazaifu | ART | Flatland | Ruins only |
| Mizusawa Castle | 2018 | Iwate Prefecture | Mizusawa | ART | Flatland | Ruins only |
| Mizusawa Yashiki (Sarashina) | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Mizutake Castle (Mikawa) | 2023 | Aichi Prefecture | Gamagôri | ART | Fortified Manor | Ruins only |
| Mochibuku Castle | 2024 | Mie Prefecture | Yokkaichi | ART | Flatland | Ruins only |
| Mochikoshi Castle (Murakami Clan Fort Network) | 2021 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Mochizuki Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Mochizuki Castle (Saku) | 2022 | Nagano Prefecture | Saku | ART | Mountaintop | Ruins only |
| Mochizukishi Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Mogusa Castle | 2020 | Tokyo | Hino | Eric | Hilltop | Ruins only |
| Moji Castle | 2022 | Fukuoka Prefecture | Kitakyūshū | 豪谷 | Mountaintop | Ruins only |
| Momochi Tamba Castle | 2022 | Mie Prefecture | Nabari | 豪谷 | Hilltop | Ruins only |
| Momose Jin'ya | 2019 | Nagano Prefecture | Matsumoto | ART | Flatland | No main keep but other buildings |
| Momose Yashiki | 2022 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Mondo Castle (Azumi) | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Monjuyama Castle | 2023 | Aichi Prefecture | Shinshiro | ART | Mountaintop | No main keep but other buildings |
| Monnouchi Yashiki (Yatsushiro) | 2023 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Monomi Castle (Murakami Clan Fort Network) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Mori Castle (Hoi) | 2025 | Aichi Prefecture | Toyokawa | ART | Fortified Manor | Ruins only |
| Mori Castle (Mikawa) | 2023 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Moriguchi Castle | 2025 | Osaka | Moriguchi | ART | Flatland | Ruins only |
| Morioka Castle | 2002 | Iwate Prefecture | Morioka | Eric | Hilltop | Ruins only |
| Moriya Castle | 2017 | Ibaraki Prefecture | Moriya | Eric | Flatland | Ruins only |
| Moriyama Castle | 2017 | Fukushima Prefecture | Koriyama | ART | Mountaintop | Ruins only |
| Moriyama Castle (Izu) | 2021 | Shizuoka Prefecture | Izunokuni | ART | Mountaintop | Ruins only |
| Moriyama Castle (Owari) | 2021 | Aichi Prefecture | Nagoya | ART | Hilltop | Ruins only |
| Moroto Castle | 2013 | Chiba Prefecture | Inba | Eric | Hilltop | Ruins only |
| Motai Castle (Hanishina) | 2021 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Moto Castle (Chikuma) | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Motodoriyama Castle | 2023 | Nagano Prefecture | Iizuna | ART | Mountaintop | Ruins only |
| Motodoriyamako Castle | 2023 | Nagano Prefecture | Nagano | ART | Mountaintop | Ruins only |
| Motohori Yakata | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Motojuku Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Motojuku Jin'ya | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | No main keep but other buildings |
| Motojukushiro Yashiki | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Motosakura Castle | 2013 | Chiba Prefecture | Shisui Town | Eric | Hilltop | Ruins only |
| Motosu Castle | 2019 | Yamanashi Prefecture | Kawaguchiko | Eric | Mountaintop | Ruins only |
| Motoyama Castle (Chikuma) | 2020 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Motoyama Yakata | 2020 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Mukade Castle | 2022 | Gifu Prefecture | Hida | 豪谷 | Hilltop | Ruins only |
| Mukaihaguroyama Castle | 2019 | Fukushima Prefecture | Aizumisato | Eric | Mountaintop | Ruins only |
| Mukaijima Castle | 2020 | Kyoto | Kyoto | ART | Flatland | Ruins only |
| Mumo Castle | 2015 | Tochigi Prefecture | Nakagawa | Eric | Mountaintop | Ruins only |
| Murai Koya Castle | 2019 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Murakami Castle | 2011 | Niigata Prefecture | Murakami | Eric | Hilltop | Ruins only |
| Murakami Yakata | 2022 | Nagano Prefecture | Sakaki | ART | Fortified Manor | Ruins only |
| Murakamishishima Yakata | 2022 | Nagano Prefecture | Sakaki | ART | Fortified Manor | Ruins only |
| Muramatsu Castle | 2023 | Niigata Prefecture | Gosen | ART | Flatland | Ruins only |
| Muraoka Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Murasame Castle (Koka) | 2022 | Shiga Prefecture | Koka | Eric | Hilltop | Ruins only |
| Muro Castle | 2023 | Aichi Prefecture | Nishio | ART | Hilltop | Ruins only |
| Mutsuna Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Myodaiji Castle | 2023 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Myodaijiko Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Myogi Castle | 2019 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Myogiyama Noroshidai | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Myoken Yashiki | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Myokenji Castle | 2020 | Kyoto | Kyoto | ART | Hilltop | Ruins only |
| Myokenji Jinsho | 2023 | Fukui Prefecture | Tsuruga | ART | Flatland | Ruins only |
| Myokian Yakata | 2020 | Nagano Prefecture | Omachi | ART | Fortified Manor | Ruins only |
| Nabari Jinya | 2020 | Mie Prefecture | Nabari | Andrew A | Flatland | No main keep but other buildings |
| Nabebuta Castle | 2021 | Nagano Prefecture | Komoro | ART | Flatland | Ruins only |
| Nabekura Castle | 2012 | Iwate Prefecture | Tono | | Mountaintop | Ruins only |
| Nabeyama Castle (Nagato) | 2021 | Yamaguchi Prefecture | Shimonoseki | ART | Hilltop | Ruins only |
| Nabeyamajou Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Naegi Castle | 2013 | Gifu Prefecture | Nakatsugawa | | Mountaintop | Ruins only |
| Nagabayashi Fort | 2020 | Nagano Prefecture | Chino | ART | Mountaintop | Ruins only |
| Nagahama Castle | 1999 | Shiga Prefecture | Nagahama | Eric | Flatland | Reconstructed main keep |
| Nagahara Castle | 2022 | Shiga Prefecture | Yasu | ART | Flatland | No main keep but other buildings |
| Nagai Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nagaikeyama Fort | 2021 | Niigata Prefecture | Jouetsu | ART | Mountaintop | Ruins only |
| Nagakubo Castle | 2014 | Shizuoka Prefecture | Nagaizumi | Eric | Mountaintop | Ruins only |
| Nagakute Castle | 2023 | Aichi Prefecture | Nagakute | ART | Flatland | Ruins only |
| Nagamatsu Castle (Mino) | 2025 | Gifu Prefecture | Nagamatsu | ART | Flatland | Ruins only |
| Nagamine Fort | 2023 | Yamanashi Prefecture | Uenohara | ART | Mountaintop | Ruins only |
| Naganuma Castle (Shinano) | 2023 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Nagao Castle (Azumi) | 2020 | Nagano Prefecture | Azumino | ART | Hilltop | Ruins only |
| Nagaoka Castle | 2021 | Niigata Prefecture | Nagaoka | ART | Flatland | Reconstructed main keep |
| Nagaoka Castle (Omi) | 2022 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Nagasaka Yashiki | 2024 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Nagasakaue Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Nagasawa Castle | 2023 | Aichi Prefecture | Toyokawa | ART | Hilltop | Ruins only |
| Nagasawa Daikakuji Castle | 2023 | Aichi Prefecture | Toyokawa | ART | Mountaintop | Ruins only |
| Nagasawa Jin'ya | 2023 | Aichi Prefecture | Toyokawa | ART | Hilltop | No main keep but other buildings |
| Nagasawa Kannondou Castle | 2023 | Aichi Prefecture | Toyokawa | ART | Hilltop | Ruins only |
| Nagasawa Palace | 2023 | Aichi Prefecture | Toyokawa | ART | Flatland | Ruins only |
| Nagasawa Yadahime Yashiki | 2023 | Aichi Prefecture | Toyokawa | ART | Fortified Manor | Ruins only |
| Nagase Yakata | 2022 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Nagashima Castle | 2019 | Mie Prefecture | Kuwana | ART | Flatland | No main keep but other buildings |
| Nagashino Castle | 2009 | Aichi Prefecture | Shinshiro | Eric | Flatland | Ruins only |
| Nagata Jin'ya | 2023 | Saitama Prefecture | Saitama | Eric | Fortified Manor | No main keep but other buildings |
| Nagaune Fort | 2021 | Gunma Prefecture | Kanra | ART | Mountaintop | Ruins only |
| Nagayama Castle (Ina) | 2020 | Nagano Prefecture | Iida | ART | Mountaintop | Ruins only |
| Nagayama Castle (Suo) | 2021 | Yamaguchi Prefecture | Yamaguchi | ART | Mountaintop | Ruins only |
| Nagi Castle | 2025 | Osaka | Osaka | ART | Flatland | Ruins only |
| Nagisa Castle | 2019 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Nagoya Castle | 1999 | Aichi Prefecture | Nagoya | Eric | Flatland | Reconstructed main keep |
| Nagurumi Castle | 2013 | Gunma Prefecture | Minakami | Eric | Mountaintop | Ruins only |
| Najima Castle | 2020 | Fukuoka Prefecture | Fukuoka | ART | Hilltop | No main keep but other buildings |
| Naka Castle | 2015 | Saitama Prefecture | Ago | Eric | Hilltop | Ruins only |
| Nakaara Castle | 2023 | Shimane Prefecture | Tsuwano | Eric | Mountaintop | Ruins only |
| Nakagaitofuru Yashiki | 2024 | Aichi Prefecture | Toyota | ART | Fortified Manor | Ruins only |
| Nakagane Yashiki | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nakagayahori Yashiki | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Nakagome Castle (Ina) | 2020 | Nagano Prefecture | Minami-Minowa | ART | Hilltop | Ruins only |
| Nakagoshoshugo Yakata | 2020 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Nakagusuku Castle | 2015 | Okinawa Prefecture | Nakagusuku | | Mountaintop | Ruins only |
| Nakahara Yakata | 2019 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Nakahokkyu Castle | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Nakaizumi Jin'ya | 2025 | Shizuoka Prefecture | Iwata | ART | Flatland | No main keep but other buildings |
| Nakajima Castle (Azumi) | 2023 | Nagano Prefecture | Ikeda | ART | Mountaintop | Ruins only |
| Nakajima Fort | 2020 | Aichi Prefecture | Nagoya | Eric | Flatland | Ruins only |
| Nakajou Yakata (Chikuma) | 2022 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Nakajouikenotaira Fort | 2022 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Nakakaido Yakata | 2022 | Nagano Prefecture | Ikusaka | ART | Fortified Manor | Ruins only |
| Nakamaki Castle | 2022 | Yamanashi Prefecture | Yamanashi | ART | Hilltop | Ruins only |
| Nakamura Castle | 2012 | Kochi Prefecture | Shimanto | Furinkazan | Hilltop | Reconstructed main keep |
| Nakamura Castle (Azumi) | 2022 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Nakamura Castle (Soma) | 2016 | Fukushima Prefecture | Sōma | ART | Hilltop | No main keep but other buildings |
| Nakamura Yakata | 2020 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Nakamura Yashiki (Yamanashi) | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Nakamura Yashiki (Yatsushiro) | 2023 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Nakamuranotonoda Yakata | 2022 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Nakano Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Nakano Castle (Kai) | 2023 | Yamanashi Prefecture | Minami-Alps | ART | Mountaintop | Ruins only |
| Nakano Jin'ya | 2020 | Nagano Prefecture | Nakano | ART | Flatland | Ruins only |
| Nakanojin Castle | 2023 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Nakanojou Jin'ya | 2022 | Nagano Prefecture | Sakaki | ART | Flatland | Ruins only |
| Nakanomiyama Castle | 2025 | Gifu Prefecture | Ena | ART | Mountaintop | Ruins only |
| Nakao Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Nakao Castle (Kai) | 2022 | Yamanashi Prefecture | Hokuto | ART | Hilltop | Ruins only |
| Nakao Castle (Yamashiro) | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Nakasai Castle | 2020 | Ibaraki Prefecture | Shirosato | ART | Hilltop | Ruins only |
| Nakata Yashiki | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | No main keep but other buildings |
| Nakato Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Flatland | Ruins only |
| Nakatou Castle | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Nakatsu Castle | 2006 | Oita Prefecture | Nakatsu | Raffi | Flatland | Reconstructed main keep |
| Nakatsumori Yakata | 2023 | Yamanashi Prefecture | Tsuru | ART | Fortified Manor | Ruins only |
| Nakayama Castle (Suwa) | 2022 | Nagano Prefecture | Fujimi | ART | Hilltop | Ruins only |
| Nakayama Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Nakayama Fort (Mikawa) | 2023 | Aichi Prefecture | Shinshiro | ART | Mountaintop | No main keep but other buildings |
| Nakayamaniyama Fort | 2021 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Nakazaki Yashiki | 2022 | Ibaraki Prefecture | Mito | ART | Fortified Manor | No main keep but other buildings |
| Nakazawa Castle (Minochi) | 2020 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Nakazawa Yashiki (Kai) | 2022 | Yamanashi Prefecture | Chūō | ART | Fortified Manor | Ruins only |
| Nakijin Castle | 2006 | Okinawa Prefecture | Nakijin | | Mountaintop | Ruins only |
| Namazue Castle | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Hilltop | Ruins only |
| Namioka Castle | 2021 | Aomori Prefecture | Aomori | Eric | Flatland | Ruins only |
| Nanao Castle | 2006 | Ishikawa Prefecture | Nanao | Eric | Mountaintop | Ruins only |
| Nanao Castle (Iwami) | 2025 | Shimane Prefecture | Masuda | AnneMcL | Mountaintop | No main keep but other buildings |
| Nanbata Castle | 2014 | Saitama Prefecture | Fujimi | Eric | Flatland | No main keep but other buildings |
| Nanjou Yakata | 2023 | Shizuoka Prefecture | Fujinomiya | ART | Fortified Manor | Ruins only |
| Nanokaichi Jin'ya | 2022 | Gunma Prefecture | Tomioka | ART | Flatland | No main keep but other buildings |
| Nanzan Castle | 2023 | Okinawa Prefecture | Itoman City | RaymondW | Hilltop | Ruins only |
| Narai Castle | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Nariai Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Narisawa Castle | 2017 | Yamagata Prefecture | Yamagata | Eric | Mountaintop | Ruins only |
| Narisawa Noroshidai | 2022 | Yamanashi Prefecture | Yamanashi | ART | Mountaintop | Ruins only |
| Narukami Castle (Chikuma) | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Narumi Castle | 2020 | Aichi Prefecture | Nagoya | Eric | Hilltop | Ruins only |
| Naruse Castle (Asuke) | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Nasu Kanda Castle | 2015 | Tochigi Prefecture | Nakagawa | Eric | Flatland | Ruins only |
| Nata Castle | 2019 | Ishikawa Prefecture | Komatsu | ART | Mountaintop | Ruins only |
| Natsukawa Castle | 2013 | Okayama Prefecture | Okayama City | RaymondW | Flatland | No main keep but other buildings |
| Natsumichi Fort | 2022 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Natsuyama Castle | 2024 | Aichi Prefecture | Okazaki | ART | Mountaintop | Ruins only |
| Ne Castle | 2010 | Aomori Prefecture | Hachinohe | Eric | Flatland | No main keep but other buildings |
| Nechi Castle | 2021 | Niigata Prefecture | Itoigawa | ART | Mountaintop | Ruins only |
| Nechi Kamijouyama Castle | 2021 | Niigata Prefecture | Itoigawa | ART | Mountaintop | Ruins only |
| Nechi Kuriyama Castle | 2021 | Niigata Prefecture | Itoigawa | ART | Fortified Manor | Ruins only |
| Negoya Castle | 2020 | Gunma Prefecture | Takasaki | Eric | Mountaintop | Ruins only |
| Negoya Castle (Sanada) | 2020 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Nemoto Castle | 2024 | Gifu Prefecture | Tajimi | ART | Mountaintop | Ruins only |
| Nemotogoten Yashiki | 2024 | Gifu Prefecture | Tajimi | ART | Fortified Manor | Ruins only |
| Nemunoki Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nemuro Hanto Chashi Ato Gun | 2018 | Hokkaido | Nemuro | Onnajoshu | Flatland | Ruins only |
| Nezumiana Castle | 2021 | Nagano Prefecture | Matsukawa | ART | Mountaintop | Ruins only |
| Nezumiana Yakata | 2021 | Nagano Prefecture | Matsukawa | ART | Fortified Manor | Ruins only |
| Nihonmatsu Castle | 1999 | Fukushima Prefecture | Nihonmatsu | Eric | Mountaintop | No main keep but other buildings |
| Niijiro Fort | 2025 | Yamanashi Prefecture | Fuefuki | ART | Mountaintop | Ruins only |
| Niitakayama Castle | 2014 | Hiroshima Prefecture | Mihara | Eric | Mountaintop | Ruins only |
| Niiya Castle (Kouzuke) | 2021 | Gunma Prefecture | Kanra | ART | Mountaintop | Ruins only |
| Nijo Castle | 1999 | Kyoto | Kyoto | Eric | Flatland | No main keep but other buildings |
| Nijo Castle (Tochigi) | 2020 | Tochigi Prefecture | Tochigi | Eric | Mountaintop | Ruins only |
| Nijoko Castle | 2020 | Kyoto | Kyoto | ART | Flatland | Ruins only |
| Nikaidou Yakata | 2022 | Yamanashi Prefecture | Kōshū | ART | Fortified Manor | Ruins only |
| Nikki Castle (Nukata) | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ninomiya Castle (Musashi) | 2023 | Tokyo | Akiruno | ART | Hilltop | Ruins only |
| Nirasaki Jin'ya | 2022 | Yamanashi Prefecture | Nirasaki | ART | Flatland | Ruins only |
| Nirayama Castle | 2012 | Shizuoka Prefecture | Izunokuni | Eric | Mountaintop | Ruins only |
| Nirayama Daikansho | 2021 | Shizuoka Prefecture | Izunokuni | ART | Flatland | No main keep but other buildings |
| Nirekubo Yakata | 2021 | Nagano Prefecture | Chikuhoku | ART | Fortified Manor | Ruins only |
| Nirengi Castle | 2023 | Aichi Prefecture | Toyohashi | ART | Flatland | Ruins only |
| Nishi Aoki Castle | 2019 | Shiga Prefecture | Koka | ART | Mountaintop | Ruins only |
| Nishi Kuramae Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nishi Sakabe Castle | 2025 | Mie Prefecture | Yokkaichi | ART | Mountaintop | Ruins only |
| Nishi Wada Castle | 2023 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Nishiachiwa Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nishijou Castle | 2020 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Nishijou Castle (Chikuma) | 2021 | Nagano Prefecture | Chikuhoku | ART | Mountaintop | Ruins only |
| Nishikata Castle | 2019 | Tochigi Prefecture | Tochigi City | Eric | Mountaintop | Ruins only |
| Nishikawa Yashiki (Kai) | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | No main keep but other buildings |
| Nishimaki Castle (Azumi) | 2020 | Nagano Prefecture | Matsumoto | ART | Mountaintop | Ruins only |
| Nishina Castle | 2020 | Nagano Prefecture | Omachi | ART | Fortified Manor | Ruins only |
| Nishinahon Castle | 2022 | Nagano Prefecture | Ômachi | ART | Flatland | Ruins only |
| Nishinohara Fort | 2022 | Yamanashi Prefecture | Kōshū | ART | Hilltop | Ruins only |
| Nishio Castle | 2009 | Aichi Prefecture | Nishio | Eric | Flatland | No main keep but other buildings |
| Nishiohhira Jin'ya | 2022 | Aichi Prefecture | Okazaki | 豪谷 | Flatland | No main keep but other buildings |
| Nishiyama Castle (Azumi) | 2019 | Nagano Prefecture | Ōmachi | ART | Mountaintop | Ruins only |
| Nishiyama Castle (Chiisagata) | 2022 | Nagano Prefecture | Ueda | ART | Mountaintop | Ruins only |
| Nitchu Castle | 2021 | Toyama Prefecture | Kamiichi | ART | Hilltop | Ruins only |
| Niwase Castle | 2013 | Okayama Prefecture | Okayama City | RaymondW | Flatland | Ruins only |
| Niwaya Castle (Kozuke) | 2021 | Gunma Prefecture | Kanra | ART | Fortified Manor | Ruins only |
| Nobata Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nobeoka Castle | 2013 | Miyazaki Prefecture | Nobeoka | Frank T. | Hilltop | No main keep but other buildings |
| Nobutora Tanjou Yashiki | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Nochiseyama Castle | 2014 | Fukui Prefecture | Obama | RaymondW | Mountaintop | Ruins only |
| Noda Castle (Hekikai) | 2023 | Aichi Prefecture | Kariya | ART | Flatland | Ruins only |
| Noda Castle (Settsu) | 2025 | Osaka | Osaka | ART | Flatland | Ruins only |
| Noda Castle (Shitara) | 2024 | Aichi Prefecture | Shinshiro | ART | Hilltop | Ruins only |
| Noge Yakata | 2025 | Kyoto | Nantan | Eric | Fortified Manor | Ruins only |
| Noguchi Castle (Mikawa) | 2025 | Aichi Prefecture | Toyokawa | ART | Mountaintop | Ruins only |
| Noguchi Kaminoyama Castle | 2025 | Aichi Prefecture | Toyokawa | ART | Mountaintop | Ruins only |
| Noguchi Yakata | 2021 | Gifu Prefecture | Kakamigahara | ART | Fortified Manor | Ruins only |
| Noji Castle | 2025 | Shizuoka Prefecture | Hamamatsu | ART | Flatland | No main keep but other buildings |
| Nomi Castle (Nukata) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Nomura Castle (Tanba) | 2021 | Hyogo Prefecture | Tanba | ART | Fortified Manor | Ruins only |
| Nomura Fort | 2021 | Nagano Prefecture | Shiojiri | ART | Mountaintop | Ruins only |
| Nomura Jin'ya (Mino) | 2025 | Gifu Prefecture | Ohno | ART | Flatland | No main keep but other buildings |
| Nomura Yakata | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Norisada Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Norisada Jin'ya | 2024 | Aichi Prefecture | Toyota | ART | Hilltop | Ruins only |
| Norisada Kobata Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Nosezakanishi Castle | 2022 | Yamanashi Prefecture | Yamanashi | ART | Mountaintop | Ruins only |
| Notose Castle (Omi) | 2022 | Shiga Prefecture | Maibara | ART | Fortified Manor | Ruins only |
| Nouken Castle | 2022 | Yamanashi Prefecture | Nirasaki | ART | Hilltop | Ruins only |
| Nouken Dousaka Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Hilltop | Ruins only |
| Nouken Kurokoma Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Mountaintop | Ruins only |
| Nouken Nishi Fort | 2022 | Yamanashi Prefecture | Nirasaki | ART | Hilltop | Ruins only |
| Nozaki Castle | 2023 | Osaka | Daito | Eric | Mountaintop | Ruins only |
| Nubaku Yakata | 2023 | Yamanashi Prefecture | Fuefuki | ART | Fortified Manor | Ruins only |
| Numata Castle | 2013 | Gunma Prefecture | Numata | Eric | Mountaintop | Ruins only |
| Numatashi Dejiro | 2025 | Fukui Prefecture | Wakasa | Eric | Mountaintop | Ruins only |
| Nyoigatake Castle | 2022 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Nyunomi Castle | 2021 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Oba Castle | 2018 | Kanagawa Prefecture | Fujisawa | Eric | Hilltop | Ruins only |
| Obama Castle | 2014 | Fukui Prefecture | Obama | RaymondW | Flatland | Ruins only |
| Obama Castle (Iwashiro) | 2016 | Fukushima Prefecture | Nihonmatsu City | ART | Mountaintop | Ruins only |
| Obara Castle | 2018 | Ibaraki Prefecture | Kasama | ART | Flatland | Ruins only |
| Obaraichiba Castle | 2022 | Aichi Prefecture | Toyota | 豪谷 | Mountaintop | Ruins only |
| Obata Castle | 2016 | Ibaraki Prefecture | Ibaraki | Eric | Flatland | Ruins only |
| Obata Castle (Tanba) | 2025 | Kyoto | Ayabe | Eric | Mountaintop | Ruins only |
| Obata Jin'ya | 2016 | Gunma Prefecture | Kanra | Eric | Flatland | No main keep but other buildings |
| Obi Castle | 2012 | Miyazaki Prefecture | Nichinan | Frank T. | Hilltop | No main keep but other buildings |
| Obiki Castle | 2016 | Nagano Prefecture | Ueda | Eric | Mountaintop | Ruins only |
| Obinata Samon Yakata | 2021 | Nagano Prefecture | Nagano | ART | Fortified Manor | Ruins only |
| Obu Yashiki (Kai) | 2022 | Yamanashi Prefecture | Kai | ART | Fortified Manor | Ruins only |
| Ochaya Yashiki | 2024 | Gifu Prefecture | Ôgaki | ART | Flatland | No main keep but other buildings |
| Ochiai Fort | 2025 | Gifu Prefecture | Ena | ART | Mountaintop | Ruins only |
| Ochiai Yakata | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Ochiai Yashiki | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | No main keep but other buildings |
| Ochiai Yashiki (Ochiai) | 2022 | Yamanashi Prefecture | Kōfu | ART | Fortified Manor | Ruins only |
| Oda Castle | 2016 | Ibaraki Prefecture | Tsukuba | Eric | Flatland | Ruins only |
| Odaka Castle | 2013 | Aichi Prefecture | Nagoya | RaymondW | Hilltop | Ruins only |
| Odani Castle | 2010 | Shiga Prefecture | Nagahama | | Mountaintop | Ruins only |
| Odano Castle | 2016 | Tokyo | Hachioji | Eric | Hilltop | Ruins only |
| Odano Castle (Kai) | 2024 | Yamanashi Prefecture | Yamanashi | ART | Mountaintop | Ruins only |
| Odawara Castle | 1999 | Kanagawa Prefecture | Odawara | Eric | Hilltop | Reconstructed main keep |
| Odayama Castle (Aizu) | 2019 | Fukushima Prefecture | Aizu-Wakamatsu | ART | Mountaintop | Ruins only |
| Odoi | 2020 | Kyoto | Kyoto | ART | Flatland | Ruins only |
| Odori Castle | 2020 | Saitama Prefecture | Matsuyama | Eric | Flatland | Ruins only |
| Odoriba Fort | 2021 | Nagano Prefecture | Suwa | ART | Mountaintop | Ruins only |
| Ogaki Castle | 1999 | Gifu Prefecture | Ogaki | Eric | Flatland | Reconstructed main keep |
| Ogawa Castle | 2013 | Gunma Prefecture | Minakami | Eric | Hilltop | Ruins only |
| Ogawa Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Ogawa Castle (Musashi) | 2023 | Tokyo | Akiruno | ART | Fortified Manor | Ruins only |
| Ogawa Castle (Omi) | 2022 | Shiga Prefecture | Higashi-Ōmi | ART | Fortified Manor | Ruins only |
| Ogawa Castle (Owari) | 2021 | Aichi Prefecture | Higashiura | ART | Flatland | No main keep but other buildings |
| Ogawa Nakanojo Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Ogawa Nishinojo Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Ogawamatobaoka Castle | 2020 | Aichi Prefecture | Anjo | ART | Fortified Manor | Ruins only |
| Ogawara Yakata | 2022 | Nagano Prefecture | Suzaka | ART | Fortified Manor | Ruins only |
| Ogawashimo Castle | 2023 | Aichi Prefecture | Anjō | ART | Fortified Manor | Ruins only |
| Ogi Castle (Nukata) | 2023 | Aichi Prefecture | Kōta | ART | Fortified Manor | Ruins only |
| Ogimachi Castle | 2016 | Gifu Prefecture | Shirakawa | Eric | Mountaintop | Ruins only |
| Ogiwara Castle (Azumi) | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Ogiwara Yakata (Azumi) | 2022 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Ogoe Castle | 2016 | Fukushima Prefecture | Tamura | ART | Mountaintop | Ruins only |
| Oguchi Castle | 2019 | Aichi Prefecture | Ōguchi | ART | Flatland | No main keep but other buildings |
| Ogura Castle | 2011 | Saitama Prefecture | Tokigawa | Eric | Mountaintop | Ruins only |
| Ogura Castle (Azumi) | 2020 | Nagano Prefecture | Azumino | ART | Mountaintop | Ruins only |
| Ogura Castle (Omi) | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Hilltop | Ruins only |
| Ogurayama Castle | 2015 | Gifu Prefecture | Mino | ART | Hilltop | No main keep but other buildings |
| Ogurayamagami Castle | 2021 | Shiga Prefecture | Higashi-Oumi | ART | Hilltop | Ruins only |
| Oguro Castle (Ina) | 2020 | Nagano Prefecture | Ina | ART | Hilltop | Ruins only |
| Ogyu Castle | 2020 | Aichi Prefecture | Toyota | Eric | Mountaintop | Ruins only |
| Ogyuyamanaka Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Oh'eda Castle | 2017 | Fukushima Prefecture | Date City | ART | Mountaintop | Ruins only |
| Oh'ide Castle | 2020 | Nagano Prefecture | Minowa | ART | Hilltop | Ruins only |
| Oh'idefuru Castle | 2020 | Nagano Prefecture | Minowa | ART | Hilltop | Ruins only |
| Oh'ikemurayama Castle | 2020 | Nagano Prefecture | Yamagata | ART | Mountaintop | Ruins only |
| Oh'ino Castle (Mikawa) | 2024 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Oh'iwa Castle | 2022 | Nagano Prefecture | Suzaka | ART | Fortified Manor | Ruins only |
| Oh'uchi Yakata | 2021 | Yamaguchi Prefecture | Yamaguchi | ART | Fortified Manor | No main keep but other buildings |
| Oh'yama no Saku | 2023 | Yamagata Prefecture | Tsuruoka | ART | Flatland | Ruins only |
| Ohbayashi Yashiki | 2023 | Yamanashi Prefecture | Hokuto | ART | Fortified Manor | Ruins only |
| Ohdairashin Castle (Izu) | 2021 | Shizuoka Prefecture | Numazu | ART | Mountaintop | Ruins only |
| Ohdate | 2021 | Akita Prefecture | Noshiro | Eric | Mountaintop | Ruins only |
| Ohfuji Castle | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Ohga Castle | 2020 | Gifu Prefecture | Yamagata | ART | Mountaintop | Ruins only |
| Ohguma Castle | 2020 | Nagano Prefecture | Suwa | ART | Hilltop | Ruins only |
| Ohhara Castle | 2013 | Shiga Prefecture | Koka | RaymondW | Fortified Manor | Ruins only |
| Ohhata Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Hilltop | Ruins only |
| Ohhira Higashiohmori Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohhira Okado Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohhira Saikatsu Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohhira Tsujishige Castle | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohkawarashi Castle (Koka) | 2023 | Shiga Prefecture | Koka | Eric | Mountaintop | Ruins only |
| Ohkouchi Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohkubo Castle (Ina) | 2020 | Nagano Prefecture | Komagane | ART | Hilltop | Ruins only |
| Ohkubo Jin'ya (Mikawa) | 2023 | Aichi Prefecture | Kōta | ART | Flatland | Ruins only |
| Ohkunugi Yakata | 2023 | Yamanashi Prefecture | Uenohara | ART | Fortified Manor | Ruins only |
| Ohkusa Castle (Chita) | 2017 | Aichi Prefecture | Chita | ART | Flatland | Reconstructed main keep |
| Ohkusa Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Ohmachi Kitahara Yakata | 2021 | Nagano Prefecture | Ômachi | ART | Fortified Manor | Ruins only |
| Ohmachi Minamihara Yakata | 2021 | Nagano Prefecture | Ômachi | ART | Fortified Manor | Ruins only |
| Ohmatsuyama Castle | 2024 | Okayama Prefecture | Takahashi | Furinkazan | Mountaintop | Ruins only |
| Ohmine Castle | 2020 | Nagano Prefecture | Nagano | ART | Mountaintop | Reconstructed main keep |
| Ohmiya Castle (Suruga) | 2023 | Shizuoka Prefecture | Fujinomiya | ART | Flatland | Ruins only |
| Ohmiyahachiman Yakata | 2021 | Nagano Prefecture | Shiojiri | ART | Fortified Manor | Ruins only |
| Ohmizo Castle | 2012 | Shiga Prefecture | Takashima | RaymondW | Flatland | Ruins only |
| Ohmizo Jin'ya | 2024 | Shiga Prefecture | Takashima | Eric | Flatland | Ruins only |
| Ohmori Castle | 2017 | Fukushima Prefecture | Fukushima City | ART | Mountaintop | No main keep but other buildings |
| Ohmori Castle (Mino) | 2025 | Gifu Prefecture | Kani | ART | Mountaintop | Ruins only |
| Ohmori Daikansho | 2020 | Shimane Prefecture | Oda | ART | Flatland | No main keep but other buildings |
| Ohmura Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Ohmura Yashiki | 2022 | Yamanashi Prefecture | Yamanashi | ART | Fortified Manor | Ruins only |
| Ohniwa Castle (Ina) | 2022 | Nagano Prefecture | Tatsuno | ART | Fortified Manor | Ruins only |
| Ohno Castle (Chikuzen) | 2013 | Fukuoka Prefecture | Ohno | ART | Mountaintop | Ruins only |
| Ohno Castle (Chita) | 2017 | Aichi Prefecture | Tokoname | ART | Hilltop | Reconstructed main keep |
| Ohno Fort | 2022 | Yamanashi Prefecture | Yamanashi | ART | Flatland | Ruins only |
| Ohnoda Castle | 2024 | Aichi Prefecture | Shinshiro | ART | Hilltop | Ruins only |
| Ohnoda Castle (Azumi) | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Ohnuma Castle | 2025 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Ohsaki Castle | 2022 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Ohsakide Castle | 2022 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Ohsawa Castle (Mikawa) | 2025 | Aichi Prefecture | Toyokawa | ART | Hilltop | Ruins only |
| Ohshima Jin'ya | 2024 | Aichi Prefecture | Toyota | ART | Hilltop | Ruins only |
| Ohshio Castle (Azumi) | 2023 | Nagano Prefecture | Ômachi | ART | Mountaintop | Ruins only |
| Ohtaki Castle (Mikawa) | 2023 | Aichi Prefecture | Toyokawa | ART | Hilltop | Ruins only |
| Ohtaridaira Yakata | 2021 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Ohtawara Castle | 2018 | Tochigi Prefecture | Ohtawara | ART | Hilltop | Ruins only |
| Ohtou Castle | 2023 | Nagano Prefecture | Nagano | ART | Flatland | Ruins only |
| Ohtsu Castle | 2021 | Shiga Prefecture | Otsu | ART | Flatland | Ruins only |
| Ohtsubo Fort | 2023 | Yamanashi Prefecture | Hokuto | ART | Hilltop | Ruins only |
| Ohtsubono Fort | 2023 | Yamanashi Prefecture | Hokuto | ART | Hilltop | Ruins only |
| Ohtsuka Moated Settlement | 2023 | Kanagawa Prefecture | Yokohama | ART | Hilltop | No main keep but other buildings |
| Ohtsuma Yakata | 2020 | Nagano Prefecture | Azumino | ART | Fortified Manor | Ruins only |
| Ohwatari Noroshidai | 2025 | Yamanashi Prefecture | Hokuto | ART | Mountaintop | Ruins only |
| Ohyama Dejiro | 2023 | Kyoto | Kyoto | Eric | Mountaintop | Ruins only |
| Ohzuku Castle | 2024 | Shiga Prefecture | Nagahama | ART | Mountaintop | Ruins only |
| Oi Castle (Mikawa) | 2023 | Aichi Prefecture | Okazaki | ART | Fortified Manor | Ruins only |
| Oike Fort | 2020 | Nagano Prefecture | Matsumoto | ART | Hilltop | Ruins only |
| Oishi Castle (Bitchu) | 2022 | Okayama Prefecture | Okayama | ART | Mountaintop | Ruins only |
| Oiwakehikage Castle | 2024 | Aichi Prefecture | Toyota | ART | Mountaintop | Ruins only |
| Oiwayama Fort | 2025 | Shiga Prefecture | Nagahama | Eric | Mountaintop | Ruins only |
| Ojima Castle (Mikawa) | 2023 | Aichi Prefecture | Nishio | ART | Hilltop | Ruins only |
| Ojima Castle (Mino) | 2025 | Gifu Prefecture | Ibigawa | ART | Mountaintop | Ruins only |
| Ojima Jin'ya | 2016 | Shizuoka Prefecture | Shizuoka | Eric | Flatland | No main keep but other buildings |
| Oka Castle | 2006 | Oita Prefecture | Taketa | Raffi | Mountaintop | Ruins only |
| Oka Castle (Mikawa) | 2022 | Aichi Prefecture | Okazaki | 豪谷 | Flatland | Ruins only |
| Okada Chikayoshi Yakata | 2021 | Nagano Prefecture | Matsumoto | ART | Fortified Manor | Ruins only |
| Okami Castle | 2017 | Ibaraki Prefecture | Ushiku | Eric | Hilltop | Ruins only |
| Okaya Castle (Suwa) | 2019 | Nagano Prefecture | Okaya | ART | Hilltop | Ruins only |
| Okayama Castle | 2006 | Okayama Prefecture | Okayama | Eric | Hilltop | Reconstructed main keep |
| Okayama Jin'ya | 2023 | Aichi Prefecture | Nishio | ART | Flatland | No main keep but other buildings |
| Okayama Jinjiro | 2022 | Gifu Prefecture | Ogaki | 豪谷 | Mountaintop | Ruins only |
| Okazaki Castle | 1999 | Aichi Prefecture | Okazaki | Eric | Hilltop | Reconstructed main keep |
