is a Japanese novel series written by Keigo Higashino. The series began publication by Jitsugyo no Nihon Sha in March 2020, with three volumes being released as of May 2025. An anime film adaptation of the first novel produced by A-1 Pictures and Psyde Kick Studio premiered in Japan in January 2026.
An anime film adaptation of the first novel was announced on April 8, 2025. The film is produced by A-1 Pictures and Psyde Kick Studio and directed by Tomohiko Ità Â, with Taku Kishimoto writing the screenplay and Tsubasa Yamaguchi, Akiko Itagaki designing the characters, and Yugo Kanno composing the music. It was released in Japan by Aniplex on January 30, 2026. The theme song is performed by Uru.
The first novel has over one million copies in circulation.