LiSA’s Gurenge will forever be synonymous with Demon Slayer, but the series has been known to feature quite a few bangers in its intro and outro sequences. The Infinity Castle movies are no different. Here’s what you need to know about the intro song that plays in Demon Slayer: Infinity Castle (Akaza’s Return).
Demon Slayer: Infinity Castle (Akaza’s Return) Intro Song
The intro song that plays as Demon Slayer: Infinity Castle (Akaza’s Return) begins is called A World Where the Sun Never Rises, performed by the Japanese pop singer Aimer. The Japanese title is 太陽が昇らない世界.
The song plays at the very start of the movie, where Tanjiro, Zenitsu, and all the active Hashiras get dropped into the titular Infinity Castle. This iconic location has been teased since Season 1, and it’s known to be the base where Muzan and his ranked Moons reside. As we get reintroduced to all our main characters and get a feel for their locations and where they’re headed, as well as the threats that await them there, Aimer’s song plays, setting up the stakes for this movie.
A World Where the Sun Never Rises was originally aired on July 19, 2025, and became available for streaming and purchase on July 23, 2025. Aimer had worked with animation studio ufotable and the Demon Slayer team for this song, and it was composed specially for the Infinity Castle movie. The title and lyrics are very apt for the movie as well, as it describes a world shrouded in eternal darkness, just like the Infinity Castle itself where the sun can’t shine through. It also contains vague descriptions of resolve and past sorrows, which are in line with the emotions of our main characters, who have just suffered the loss of Ubuyashiki prior to entering the Castle.
Aimer has previously worked on other music for the Demon Slayer anime series. Namely, she performed Zankyosanka and Asa ga Kuru, which were the opening and ending songs for Season 2.
