Confidence
| Field | Confidence | Notes |
|---|---|---|
| Castle name | 99% | Center stylized brushwork unambiguously reads 岡山城 (Okayama-jō); the right-column brush 国指定史跡 ("National Designated Historic Site") matches Okayama Castle's heritage status; the OshiroBot has the distinctive black-and-gold mecha typical of the Ujō / Crow Castle color scheme; the red disc behind the brush displays the Ikeda family crest 揚羽蝶 (Ageha-chō / butterfly) stylized as a red sun. Top-right red square 御城印 seal confirms the gojōin classification. |
| Date | N/A | Date column 令和 年 月 日 left blank — typical pre-printed gojōin format. Visit estimated 1 April 2025 based on adjacent Okayama-area stamps (Kibitsuhiko Jinja and Kibitsu Ebisu-gū both dated 4月一日). |
Identification
- Name (Japanese): 岡山城 (オシロボッツ版)
- Name (Romanized): Okayama-jō (OshiroBots edition); also called 烏城 (Ujō / "Crow Castle") and 金烏城 (Kin-Ujō / "Golden Crow Castle")
- Type: 御城印 (gojōin / castle stamp) — collaboration design with 城郭合体オシロボッツ (OshiroBots), a MIXI ANIME mecha-castle franchise
- Issuance point: Okayama Castle museum gift shop / paid-entry section
- Location: Marunouchi, Kita Ward, Okayama City, Okayama Prefecture
- Date received: Date column blank; estimated 1 April 2025 (matches the adjacent Okayama-area stamps in this book)
Reading the gojōin
| Element | Reading | Position |
|---|---|---|
| 御城印 (tensho seal) | "Castle stamp" certification | Top center, red square seal |
| 国指定史跡 | "Nationally Designated Historic Site" | Right column, brush |
| 岡山城 | Okayama-jō (Okayama Castle) | Center, large stylized brush |
| Okayama Castle OshiroBot | Mecha rendering — demon-horn helmet matching the shachihoko (golden dolphins) on the actual roof; black armor for the karasujō (crow castle) lacquered black walls; golden body panels for the gold accents on the original keep | Center, line-drawing |
| 揚羽蝶 (Ageha-chō) | Stylized butterfly within the red disc — the Ikeda family crest (long-time Edo-period lords of Okayama Castle) | Center, red disc |
| Castle silhouette (background) | Outline of Okayama Castle keep and surrounding turrets | Background line drawing |
| 城郭合体オシロボッツ ©MIXI | Series logo and copyright | Bottom |
| 令和 年 月 日 | Date (Reiwa year/month/day) — left blank | Left side |
Why "Crow Castle" (烏城)
Okayama Castle's distinctive black-lacquered exterior wood paneling earned it the nickname 烏城 (U-jō / Karasu-jō / "Crow Castle"). This is in deliberate contrast to 白鷺城 (Shirasagi-jō / "White Heron Castle") — Himeji Castle, ~80 km west — whose white-plastered exterior is the opposite. The two are sometimes called the "black-and-white pair of Sanyō". The roof tiles also originally had gold leaf accents including the famous shachihoko (鯱) golden-dolphin roof finials, giving rise to the alternate name 金烏城 (Kin-Ujō / "Golden Crow Castle").
About Okayama Castle
Construction began in 1573 by 宇喜多直家 (Ukita Naoie) and was completed by his son 宇喜多秀家 (Ukita Hideie) in 1597. Hideie was one of Toyotomi Hideyoshi's Go-Tairō (Council of Five Elders) and lord of Bizen Province at the height of his power. After the Battle of Sekigahara (1600) the Ukita were dispossessed (Hideie was exiled to Hachijō-jima for the rest of his life), and the castle passed to 小早川秀秋 (Kobayakawa Hideaki).
From 1632 onward the castle was held by the Ikeda clan (池田家) as a 315,000 koku domain — a major Tozama daimyō house that built up the city and the castle's gardens, including the famous 後楽園 (Kōrakuen) garden completed in 1700 — one of Japan's "Three Great Gardens" alongside Kanazawa's Kenroku-en and Mito's Kairaku-en.
The original keep was destroyed by US air raids in June 1945. The current keep is a 1966 ferro-concrete reconstruction, externally accurate to the original. A major 令和大改修 (Reiwa Great Renovation) completed in 2022 added new museum exhibits, and the gold accents on the roof and shachihoko were re-leafed in real gold.
The Ikeda butterfly crest
The 揚羽蝶 (Ageha-chō / "swallowtail butterfly") is the Ikeda family crest. The Ikeda were one of Japan's most powerful daimyō houses, ruling not only Okayama but also Tottori, and at peak holding combined assets of around 640,000 koku. The butterfly crest reflects an old aristocratic lineage — the Ikeda traced descent from the Heian-period Taira (Heike) clan, whose hereditary crest was also a butterfly.
What's "国指定史跡" (Nationally Designated Historic Site)?
This is the highest tier of cultural-site designation under Japan's Cultural Properties Protection Law (文化財保護法), administered by the Agency for Cultural Affairs. Okayama Castle's stone foundations, walls, and surviving Edo-period structures (the 月見櫓 / Tsukimi-yagura and 西丸西手櫓 / Nishi-no-Maru Nishi-Yagura) are designated. The wooden 1966 reconstruction itself is not (it's not original), but the site as a whole carries this status.
What it's known for
- The black-lacquered keep — the reconstructed exterior is one of the most distinctive in Japan
- 後楽園 (Kōrakuen) garden — one of Japan's Three Great Gardens, immediately adjacent across the river
- Connection to the Momotarō (桃太郎) legend — Okayama claims Momotarō as a local folk hero, and the city's mascot, manhole covers, and souvenirs are saturated with peach imagery
- The recently-renovated museum interior with extensive Ukita-clan and Ikeda-clan exhibits