The first installment of the Demon Slayer: Infinity Castle film was released on July 18th, 2025, only in Japanese theaters. Thanks to the film’s hype and surge in publicity, it broke several box office records in the country. The film’s success is also boosting the manga sales, with many fans buying the volumes after the premiere. However, it’s not just the original manga, but even the underrated spin-off Demon Slayer: Kimetsu Academy by Natsuki Hokami, is also getting reprints for all six volumes on September 16th, 2025. Having over 30 chapters, the spin-off was serialized in Saikyou Jump, a monthly Shonen magazine by Shueisha.
The spin-off is based on Junior High and High School!! Kimetsu Academy extras that appeared in the original manga. A short anime version of the extras was also released in 2020. A year later, Hokami adapted the story in a light-hearted, slice-of-life manga series. Set in a modern world, the series follows familiar characters as either teachers or students, but within a world free of demons and Breathing Techniques, an era of peace. The characters are in adorable chibi form, embodying the playful and energetic tone of the spin-off, which is a major contrast to the intense storyline of the original manga.
Demon Slayer: Infinity Castle’s Movie Sparks Reprint Demand for Dormant Spinoff
Beyond crushing the box office and having a months-long promo period to generate worldwide hype, Demon Slayer and its Infinity Castle movie have the power to renew interest in a dormant themed spinoff with Kimetsu Academy! The series is a fun interlude, now fresher than ever as it sits between installments of the Infinity Castle story with families flocking to the book as it issues out reprints. It’s a great time to be a fan, and so far, this is still largely the effects from just the domestic release in Japan.
The film will hit the U.S. theaters on September 12, 2025, and the tickets are already on sale. The story continues after Nakime, the Biwa demon, threw the Demon Slayers inside the Infinity Castle, the hideout of Muzan Kibutsuji. The castle is an endless labyrinth, brought into reality thanks to Nakime’s Blood Demon Art. She can control the layout and who goes in or out of the castle. The Demon Slayers are basically trapped in a place that is impossible to navigate. They are also scattered all over the place, which makes it easy for the demons to kill them one after the other. While a lot of the major characters can easily handle ordinary demons, the Upper Moons are not to be taken lightly.
Whether it’s Tanjiro Kamado and Giyu Tomioka vs. Akaza, Shinobu Kocho facing Doma all by herself, or Zenitsu fighting a mysterious demon, each fight has something new to offer with higher stakes than ever. The final arc of the story is not just action-driven, but it also places significant emphasis on emotional depth, weaving in multiple backstories and meaningful character development. The story will wrap up in the trilogy films, although we may have to wait a bit longer before getting any information on the second film.
H/T: @WSJ_manga on X
