Watch the Whoever Steals This Book special music video on YouTube
The film will debut on December 26, 2025, in Japanese theaters, bringing Nowaki Fukamidori's acclaimed fantasy novel to the big screen. The Whoever Steals This Book release date marks the culmination of production at Kagokan (Kagome Company), a newly established studio making its feature film debut with this ambitious adaptation. The film's premiere comes after months of anticipation following the initial announcement, with fans eager to experience the magical story of books, curses, and adventure. The film stars Rin Kataoka as Mifuyu Mikura, the book-hating protagonist who makes her voice acting debut in this role. Sora Tamaki voices Mashiro, the mysterious girl who helps Mifuyu on her adventure. The Whoever Steals This Book cast includes a mix of newcomers and veteran voice actors, with Nao Tōyama as Hirune Mikura, Junichi Suwabe as Ayumu Mikura, Shizuka Itō as Keiko Yosano, Shimba Tsuchiya as Takafumi Haruta, Romi Park as Tamaki Mikura, Shigeru Chiba as Junichirō Kaname, Ryōta Suzuki as Tanbi Che, Reina Ueda as Natsume Harada, Tomokazu Seki as Osamu Kikuchida, Rie Takahashi as Shiori Haruta, Yō Taichi as Kakihara, Makoto Koichi as Hiroda, Yumiri Hanamori as Takayama, Hitomi Ueda as Osanai, Manaka Iwami as Uhara, and Jun Fukuyama as the Mysterious Man. Daisei Fukuoka (Radiant series director, Danganronpa 3: The End of Hope's Peak High School: Despair Arc and Future Arc, Phantom of the Idol) is directing the film at Kagome Company (Kagokan). Yasuhiro Nakanishi (Kaguya-sama: Love is War, No Longer Allowed In Another World, Shy) is writing the script, ensuring the adaptation captures the novel's magical realism and adventure elements. Keiko Kurosawa (Astra Lost in Space, Asobi Asobase -workshop of fun-) is designing the characters and serving as the film's animation director, reportedly drawing half the film's keyframes herself, demonstrating exceptional dedication to the project's visual quality. Michiru Ōshima (Fullmetal Alchemist, Little Witch Academia) is composing the music, creating a score that complements YUKI's theme song and enhances the film's fantastical atmosphere. Kagokan founder Yūji Higa (Danganronpa 3: The End of Hope's Peak High School: Despair Arc, Asobi Asobase -workshop of fun-, Radiant) serves as the animation producer, bringing his experience to the studio's first feature film production. Kadokawa Animation is distributing the film, ensuring wide theatrical release across Japan. The Whoever Steals This Book studio collaboration represents a significant milestone for Kagokan, establishing the studio as a capable producer of feature-length animated films with this ambitious fantasy adaptation. Other staff members include Color Key Artists Eriko Murata and Tarō Kaguchi, CG Director Kōji Ichikawa, 2D Design by Aya Kubota, Compositing Director of Photography Yuichiro Tozawa, Editing by Kengo Shigemura, and Sound Director Fumiyuki Go. This talented production team ensures that the film delivers both visual excellence and compelling storytelling, bringing Nowaki Fukamidori's imaginative world to life on screen. Vocalist YUKI (formerly of Judy and Mary) performs the theme song "Share," which is featured prominently in the special music video released on December 25, 2025. The Whoever Steals This Book theme song "Share" by YUKI captures the emotional journey of the protagonist as she navigates through different story worlds, with YUKI's distinctive vocal style adding depth to the film's musical identity. The music video provides fans with a preview of the film's tone and visual style while showcasing the theme song's integration into the narrative. Yen On licensed and released the novel on February 18, 2025, making the source material accessible to English-speaking audiences. Yen On describes the story: "Mifuyu is a high school student living with a large collection of books left by her great-grandfather―the vast library known as Mikura Hall. Although her father is the current caretaker, Mifuyu herself doesn't share her family's passion for literature. But when several books are stolen from the library, triggering an ancient curse, the town is transformed according to the various stories―and the only way to put things right is for Mifuyu to catch the thief. With the help of a mysterious girl named Mashiro, Mifuyu sets out on an adventure through the different story worlds!" The Whoever Steals This Book plot summary emphasizes the story's unique premise of a book-hating protagonist forced to engage with literature to save her town, creating an engaging narrative that celebrates the power of stories. Kadokawa first published the novel in 2020, establishing Nowaki Fukamidori's fantasy work in the Japanese literary market. The novel was nominated for the 2021 Honya Taisho (Japan Booksellers' Award), demonstrating its critical acclaim and popularity among readers. A manga adaptation of the novel by Kakeru Sora was serialized in Kadokawa's Young Ace magazine from December 2021 to March 2023, providing a visual interpretation of the story. Yen Press released the manga's three compiled book volumes in English, making the adaptation accessible to international audiences who want to experience the story in a different format. Kadokawa published Fukamidori's spinoff novel titled Kūsō no Umi (Fantasy Sea) in May 2023, expanding the literary universe established in the original work. The Whoever Steals This Book franchise expansion demonstrates the story's enduring appeal and the author's continued creative exploration of the fantasy world, potentially setting the stage for future adaptations or sequels. The film's production represents a significant achievement for Studio Kagokan, marking the newly established studio's first full-length animated feature. The Whoever Steals This Book Studio Kagokan debut showcases the studio's capabilities in producing high-quality feature films, with Keiko Kurosawa's extensive hand-drawn keyframe work demonstrating the team's commitment to traditional animation techniques combined with modern production values. This approach creates a visually distinctive film that stands out in the 2025 anime film landscape. As the December 26, 2025 premiere approaches, anticipation continues to build among fans of the novel, manga, and newcomers discovering the story through promotional materials. The combination of experienced staff, talented voice actors, a beloved source material, and an emotional theme song creates an appealing package for viewers seeking magical realism and fantasy adventure. The Whoever Steals This Book December 2025 release will join other anticipated anime films in what promises to be an exciting end-of-year theatrical season for anime fans.Frequently Asked Questions
The film is scheduled to premiere in Japanese theaters on Friday, December 26, 2025.
The story follows Mifuyu Mikura, a high school student who lives in a town obsessed with literature and is the descendant of a famous book collector. Despite her family legacy of managing "Mikura Hall"—a massive private library—Mifuyu personally hates books. When a thief steals several volumes from the library, an ancient curse is triggered, physically transforming the town into various fictional story worlds. To break the curse and return her town to normal, Mifuyu must venture into the stories she despises and catch the thief.
Mifuyu Mikura: The protagonist, voiced by Rin Kataoka (making her voice acting debut). Mashiro: A mysterious, cool girl with dog ears who guides Mifuyu through the story worlds; she is voiced by Sora Tamaki. Hirune Mikura: Mifuyu's aunt and caretaker of the library, voiced by Nao Tōyama. Ayumu Mikura: Mifuyu's father, voiced by Junichi Suwabe.
The film is produced by Kagokan (Kagome Company, Inc.), a studio founded by veteran animation producer Yūji Higa.
The theme song is titled "Share" and is performed by the vocalist YUKI (formerly of the band Judy and Mary).
The original novel by Nowaki Fukamidori was published in Japan by Kadokawa. An official English translation was licensed and released by Yen On (an imprint of Yen Press) on February 18, 2025.
The film is directed by Daisei Fukuoka, whose previous credits include Radiant, Danganronpa 3: The End of Hope's Peak High School, and Phantom of the Idol.
Yes. A manga adaptation illustrated by Kakeru Sora was serialized in Young Ace magazine between December 2021 and March 2023. It was compiled into three volumes, all of which have been released in English by Yen Press.
The original novel was nominated for the 2021 Honya Taisho (Japan Booksellers' Award).
The film initially opens exclusively in Japanese theaters starting December 26, 2025. While Kadokawa is handling international rights and introduced the film to buyers at the 2025 Asian Contents & Film Market, specific global streaming platforms (such as Crunchyroll or Netflix) have not yet announced official release dates as of December 25, 2025.