Book and Key mystery game demo launches on Steam
The trial version covers the whole first chapter and arrives as the Switch and PC title heads toward a winter release.
SHUEISHA GAMES released a demo for its mystery adventure game based on Honobu Yonezawa's novel on Steam on October 20, 2026, the publisher announced. The trial version went live at 2:00 JST to coincide with Steam Next Fest.
The demo lets players go through the entire first chapter, titled "913". The full game is scheduled to launch for Nintendo Switch and Steam this winter.
Development is handled by iMel Inc. The story is fully voiced, and players take on the role of the protagonist to work through some of the mysteries themselves. Supported languages are Japanese, English and both traditional and simplified Chinese.
The original novel is the first entry in a series set among school library committee members, and has passed 400,000 copies in cumulative printings, according to news.denfaminicogamer.jp. A second volume is already on sale.
Yonezawa debuted in 2001 with Hyouka, which with the rest of his Classics Club series was adapted into anime, manga and a live-action film. He won the 166th Naoki Prize in 2022 for Kokurou-jo.
Quick answers
When is the game's release date?
It is scheduled to launch for Nintendo Switch and Steam in winter 2026.
What does the Steam demo include?
The demo contains the entire first chapter, "913".
Which languages does the game support?
Japanese, English, and traditional and simplified Chinese.