Whoever Steals This Book

is a Japanese novel written by Nowaki Fukamidori. It was published by Kadokawa Shoten in October 2020, with a paperback edition being released under its Kadokawa Bunko imprint in June 2023. A manga adaptation illustrated by Kakeru Sora was serialized in Kadokawa Shoten's Young Ace magazine from December 2021 to March 2023 and was compiled into three volumes. An anime film adaptation produced by Kagokan premiered in Japan in December 2025.

Premise

Mifuyu Mikura, a high school girl whose family has a long history of book collecting, has not inherited her great-grandfather and father's love for books. Her great-grandfather set up a library, known as the Mikura Hall, which became popular among the locals. However, it was closed to the public following a theft incident, with rumors spreading about the nature of its closure. One day, Mifuyu visits Mikura Hall following complaints from the neighbors. There, she encounters a talisman that came from a stolen book, warning that consequences were to happen if the book was stolen. Mifuyu then accidentally triggers a curse that transforms the town. A mysterious girl named Mashiro appears, saying that only by finding the book's thief will the town return to normal. The two set off on a journey to find the book thief and save the town.

Characters

A member of the Mikura family, which has long been known for their love of books. However, she did not inherit this interest, instead feeling disdain towards books. Her mother died when she was young, leaving her with just her father.

A mysterious and cool girl who joins Mifuyu on her journey. In contrast to Mifuyu, she is a book lover. She has the ability to turn into a white dog.

Mifuyu's aunt, who is the caretaker of Mikura Hall. As her brother Ayumu, Mifuyu's father, is in the hospital recovering from an injury, she is currently taking care of Mifuyu.

Mifuyu's father, who runs a dojo hall. He is currently hospitalized following a cycling accident.

Media

Novel

Manga

A manga adaptation illustrated by Kakeru Sora was serialized in Kadokawa Shoten's manga magazine Young Ace from December 3, 2021, to March 3, 2023. The manga's chapters were collected into three volumes from June 3, 2022, to April 4, 2023. The manga adaptation is also licensed in English by Yen Press.

Anime film

An anime film adaptation was announced on June 3, 2025. The film is produced by Kagokan and directed by Daisei Fukuoka, from a screenplay written by Yasuhiro Nakanishi, characters designed by Keiko Kurosawa, and music composed by Michiru ÃÂshima. It was released in Japan by Kadokawa Animation on December 26, 2025, after being previously scheduled for 2026. The film's theme song is "Share" performed by Yuki.

Reception

The novel was nominated for the 2021 Japan Booksellers' Award.