Oshiro turns the castles of Japan into a stamp book that you fill by going there.

The book covers 200 castles: the 100 Fine Castles of Japan (日本100名城) and the 100 that followed (続日本100名城). Each castle is a page. Step into the castle grounds, look for clues the way a curious visitor explores, and earn up to three stars.

THREE STARS PER CASTLE
★ 登城 Visited: check in when you step inside the castle area (GPS).
★★ 攻略 Captured: find enough of the castle's clues.
★★★ 制覇 Conquered: find every clue, special ones included.

CLUES ON SITE
More than 60 castles have hand-made sieges: hidden GPS points at gates, turrets and wells; photo clues; AR items that appear when you turn your camera toward them; and, at some castles, a quiz about the signboard in front of you. Dozens of other castles have simple missions generated from map data, and every castle can be visited.

CHARACTER CARDS (ゆかりの地)
Meet the people behind the castles: the Sanada, Takeda, Oda, Toyotomi, Tokugawa, Uesugi and Date families and those around them. Visit places linked to each life (castles, temples, graves, battlefields) and the card grows from bronze to silver to gold, unlocking a biography and sourced stories.

STORY ROUTES
Seven journeys, from the Sanada to the Date, each with a short chapter at every stop.

YOUR STAMP BOOK
• 登城印 visit seals: a keepsake seal for every castle you visit, to keep or share.
• Footprint map: colour in Japan's 47 prefectures and the old provinces as you travel.
• Your banner (旗印): choose a family crest and a colour.

PLAN YOUR VISIT
A map and list of all 200 castles and the castles near you. Castles with a full page add their history, opening hours, fees, where to find the 100名城 stamp and where the 御城印 is sold.

RESPECTFUL BY DESIGN
At shrines, temples and graves there are no quizzes, photos or AR items, and the app stays silent.

THREE LANGUAGES, NO ACCOUNT
日本語, English and Tiếng Việt, switchable in the app. No sign-in, no ads, no tracking: your progress stays on your phone. Your location is used only on your phone, only while the app is open, and is never sent to our server.

GOOD TO KNOW
• Oshiro is an independent app. It is not affiliated with or endorsed by the Japan Castle Foundation (日本城郭協会) or any castle. 日本100名城® and 続日本100名城® are registered trademarks of the Japan Castle Foundation. 登城印 are Oshiro keepsakes, not official 御城印.
• Map data © OpenStreetMap contributors. Photos (Wikimedia Commons and others) and all data sources are credited in the app, under About Oshiro.
• Opening hours and rules change: check the official information before you go, and follow the rules on site.