Demon Slayer: Kimetsu no Yaiba – Infinity Castle

Rather than condensing the source into a single recap feature, this project splits the closing Infinity Castle storyline across several full-length theatrical films, following the feature-length approach used earlier for the Mugen Train movie. Aniplex and Toho announced the multi-part adaptation in June 2024, right after the fourth television season concluded, and tapped director Haruo Sotozaki and Ufotable to continue the story directly from that season.

The opening chapter, subtitled Akaza Returns, reached Japanese screens on July 18, 2025. International distribution began in Thailand on August 12, 2025 through Crunchyroll and Sony Pictures, with further Asian markets added through August before a broader global release in September. A streaming debut was slated for 2026. Aimer and LiSA each contributed theme songs, while Yuki Kajiura and Go Shiina handled the score.

As Kagaya Ubuyashiki nears death, he warns Gyomei that simply severing Muzan's head will not be enough, urging the Hashira to hold out until daybreak. When Muzan appears at the Ubuyashiki estate, Tanjiro and the Hashira are cast down into the demons' lair, the Infinity Castle, where Nakime constantly reshapes the corridors to scatter and isolate the slayers.

Shinobu confronts Upper Rank Two, the demon who slew her sister Kanae. Though she poisons him repeatedly, he adapts to each dose, and he eventually crushes her and absorbs her body, witnessed by a horrified Kanao. Elsewhere, Zenitsu faces Kaigaku, a former fellow student turned Upper Rank Six, and ends the duel with a self-created technique before reuniting briefly in spirit with their late master.

Tanjiro and Giyu corner Akaza, the killer of Kyojuro Rengoku. Giyu awakens his Demon Slayer Mark, and Tanjiro reaches the Transparent World and the Selfless State to bypass Akaza's predictive sense and take his head. Akaza fights on regardless until memories of his human life as Hakuji, including his lost love Koyuki, overwhelm him, and he chooses to end himself in atonement. Meanwhile Muzan remains concealed within a cocoon, taunting the Corps while the battle rages on.

The first film opened to record-breaking numbers in Japan. Its debut day brought in roughly 1.64 billion yen with about 1.15 million admissions, the largest opening day in the country's box office history, and its third day set a new single-day revenue record. The three-day total of around 5.52 billion yen marked the biggest opening weekend ever recorded for Japanese cinema, and within eight days the film passed 10 billion yen, the fastest any title had reached that mark and surpassing the earlier Mugen Train feature.

Overseas, the film took in about 70 million dollars during its United States opening weekend, the largest such debut for a foreign release in that market and a record start among R-rated animated titles. On the review aggregator Rotten Tomatoes it held a 98 percent approval rating based on 50 reviews.