First Demon Slayer: Infinity Castle movie confirms its unusually long runtime

The first Demon Slayer: Infinity Castle movie is all set to premiere in Japan on July 18, 2025, and is part of the highly anticipated movie trilogy from the globally renowned shonen anime.

In a new update by the film's official website, the first installment, titled Demon Slayer: Mugen Castle Arc Chapter 1: The Return of the Monkey, will have a long runtime of 155 minutes, or 2 hours and 35 minutes. This addresses several questions about Studio Ufotable’s approach to adapting the beloved manga arc.

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Demon Slayer: Infinity Castle movie’s 155-minute runtime remains consistent with Studio Ufotable's track record

Demon Slayer, written by Koyoharu Gotouge, is an immensely popular anime that has been airing since 2019. The series is rapidly approaching its finale, as the final arcs are adapted through a trilogy of movies animated by Studio Ufotable.

While the manga has a fanbase, the studio has gained a reputation for adding anime-only scenes that elevate the source material and enhance the viewing experience. This was evident through the Hashira Training Arc, where 12 chapters were adapted into an entire anime season.

Based on its runtime, the group seems to be repeating the same trend as the first Demon Slayer: Infinity Castle movie. The main trailer of the film indicated that it would adapt three major battles - Doma vs Shinobu, Zenitsu vs Kaigaku, and Tanjiro and Giyu vs Akaza.

At most, this would cover around 20 manga chapters, which do not generally need such an extensive runtime. However, the announcement of the movie's length reinforces the belief that Studio Ufotable will be taking creative liberties by adding original scenes, heightening each battle's intensity and emotional impact.

Along with runtime, the announcement of the first Demon Slayer: Infinity Castle movie highlighted how it would be part of the world’s fastest screening. This is because the movie will be shown from midnight on July 18 across 24 theatres in 11 Japanese prefectures.

Akaza as seen in the anime (Image via Studio Ufotable)

The film has received an official rating of PG-12, but those under 18 will not be allowed to enter the initial screening due to local laws related to late-night showings. For most global audiences, however, Demon Slayer: Infinity Castle will be available in theatres starting from September 12, as reported by Crunchyroll.

The first Demon Slayer: Infinity Castle movie will pick up from the ending of the Hashira Training Arc, where the Demon Slayers were lured into Muzan’s Infinity Castle. While here, they will face off against the Upper Moon Demons to end their tyranny and save the world.

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