A Customer Request Sparked the Idea
Okada Shokai, the Osaka-based company behind the online stamp shop Inkan Hanko SHOP Hankos, built this entire product line around a single piece of customer feedback: "Do you have stamps we can use for back-and-forth with teachers?" The result is the Haikyu!! Mimashita Hanko, a self-inking stamp that pairs a chibi Haikyu!! character with a short message.
The concept targets a very specific Japanese routine. Parents and teachers exchange handwritten notes through communication notebooks (連絡帳) and reading-aloud cards (音読カード) that travel between school and home daily. A small stamp acknowledging "I saw this" replaces a plain checkmark with something that actually makes the recipient smile.
24 Characters, 7 Messages, 168 Combinations
The stamp lineup features 24 chibi character illustrations drawn from the Haikyu!! anime cast. Each design can be paired with one of seven text options: "みました" (seen it), "すごい！" (amazing!), "OK!", and four others. That gives buyers 168 possible configurations to choose from.
The stamp face measures 10mm in diameter. Buyers also pick from nine body colors and four ink colors, so the physical stamp itself can be personalized beyond just the design face. Okada Shokai positions the product for school use, but the PR TIMES release also pitches it for workplace sticky notes, shared documents, and any routine paperwork that could use a lighter touch.
Okada Shokai's Anime Stamp Playbook
This is far from Okada Shokai's first anime collaboration. The company has released similar stamp collections for My Hero Academia (including emblem-style wax sealing stamps), Jujutsu Kaisen, Natsume's Book of Friends, and even Godzilla. The Haikyu!! line already includes a separate "School Icon & Banner Stamp Collection" featuring logos from the 20 schools that appear in the anime. The Mimashita Hanko adds a communication-focused product to that existing Haikyu!! range.
The stamps are available now through Okada Shokai's Rakuten and Yahoo Shopping storefronts. No international storefront has been announced, though the company does operate a separate English-language brand called Fanco for some of its licensed products.
Looking Ahead
The Haikyu!! franchise remains active heading into 2027, with both a second theatrical film, Haikyu!! VS The Little Giant, and a special anime, Haikyu!! Bakemono-tachi no Iku Tokoro (Where the Monsters Go), confirmed for release. For fans outside Japan interested in the stamps themselves, Okada Shokai's Rakuten and Yahoo Shopping listings are Japan-only at present, though third-party proxy shipping services like Buyee and ZenMarket support Rakuten purchases. No pricing was listed in the press release.