Demon Slayer: Infinity Castle sends Tanjiro and the other swordsmen into the stronghold of Muzan, the leader of the demons. It continues the Hashira Training anime arc and opens a trilogy of films about the final battle.
Existing fans have a reason to watch: visually ambitious fights bring familiar characters face to face with opponents tied to their stories. The main caveat is that this 155-minute film repeatedly pauses its battles to revisit the past. This review does not reveal fight outcomes.
Infinity Castle at a glance
| Studio / director | ufotable / Haruo Sotozaki |
|---|---|
| Original work | Koyoharu Gotoge’s manga; the first Infinity Castle film |
| Episodes / seasons | The first film of a trilogy |
| Premiere | 2025; Japanese theatrical release on 18 July 2025 |
| Running time | 155 minutes |
| Music | Yuki Kajiura and Go Shiina |
| Japanese cast | Natsuki Hanae (Tanjiro), Hiro Shimono (Zenitsu), Takahiro Sakurai (Giyu), Saori Hayami (Shinobu), Akira Ishida (Akaza), Mamoru Miyano (Doma) |
| Theme songs | Aimer: A World Where the Sun Never Rises; LiSA: Shine in the Cruel Night |
| Where to watch | The official notice announces Crunchyroll streaming from 28 July 2026; availability in Vietnam should be checked on the service |
Review scope
This article covers the first Infinity Castle theatrical film, running 155 minutes. It is an editorial assessment based on official information, promotional material and the criticism linked below. OtaHub has no documented firsthand screening record, so it cannot assess a particular cinema’s projection or sound system.
Story: the swordsmen enter the final battle
Infinity Castle is a fortress whose interior can change. The swordsmen are separated inside it and must confront powerful demons serving Muzan. The film moves between groups instead of following Tanjiro throughout.
This gives the battle a wider scale, but assumes that viewers remember the anime’s characters: whom they have lost, which enemies they have met and why a particular encounter matters now. It does not spend much time retelling Tanjiro’s entire journey.
One important expectation is that the story continues in later films. Individual confrontations take place here, but the larger war with Muzan is not resolved. Anyone seeking a self-contained film may find its ending less satisfying.
Characters: why does each fight matter?
Shinobu, Zenitsu, Tanjiro and Giyu have more at stake than defeating a powerful opponent. Encounters inside the castle connect with established relationships and earlier events. Existing viewers can understand why someone feels anger, fear or particular determination.
The film also explores opponents’ pasts, including Akaza’s. These scenes add context, but their details are omitted here to preserve surprises. The central challenge is maintaining a battle’s tension while explaining the emotions behind it.
The Japanese cast retains Natsuki Hanae as Tanjiro, Hiro Shimono as Zenitsu and Takahiro Sakurai as Giyu. Saori Hayami, Akira Ishida and Mamoru Miyano play Shinobu, Akaza and Doma respectively. Familiar voices help connect the film to the anime.
Animation and visuals: the battles are the main attraction
The changing castle creates different opportunities to move and attack. Characters can be separated or forced to reposition during a confrontation. Sword techniques and effects are therefore only part of the action: where someone stands within the castle also matters.
This is OtaHub’s strongest category for the film. Its scale and movement give the theatrical instalment a distinct appeal. Calling it the best animation in anime history would go beyond this review’s scope, however. This article assesses one film rather than ranking it above every other animated work.
Music and voices: a familiar production team
Yuki Kajiura and Go Shiina return for the score. The official theme songs are Aimer’s A World Where the Sun Never Rises and LiSA’s Shine in the Cruel Night.
Returning composers and voice actors maintain continuity with the anime, an advantage for existing fans. The sound a viewer hears also depends on the venue, film presentation and equipment. This article does not assess any particular cinema’s sound system.
Direction and pacing: why can flashbacks feel frustrating?
A flashback revisits a character’s past. Here, these scenes appear within fights to explain why someone acts as they do. They add useful context, but put the current battle on hold.
If you want to know immediately how someone will escape danger, a lengthy flashback can be frustrating. If you care more about the character’s history, the same scene may make the fight more moving. Viewers can respond differently, and a flashback is not automatically a flaw.
OtaHub therefore does not describe the entire film as slow. The battles can be engaging while repeated shifts between past and present make the storytelling uneven. Visuals score higher than direction and pacing because those categories assess different things.
A notable detail without outcome spoilers
Promotional material shows the castle changing around the swordsmen. It creates danger rather than simply providing scenery, forcing characters to find routes and maintain their positions. This is a clear example of the setting contributing to the action.
For viewers in Vietnam: what to watch first and where to look
Watch the anime through Hashira Training first. The Mugen Train film and television adaptation cover overlapping events, so you do not need both just to follow the main story.
Aniplex’s notice announces Crunchyroll streaming from 28 July 2026 and includes Vietnamese subtitles. Before subscribing specifically for this film, check whether the title and subtitle option are available to your account in Vietnam.
How do other critics assess it?
The Guardian awarded four out of five stars. GamesRadar values the confrontations and character emotions despite an ongoing larger story. These are individual assessments, rather than proof that every viewer will feel the same way.
OtaHub emphasises the visuals and the film’s appeal to existing fans. The qualifications are lengthy flashbacks and reliance on earlier anime instalments. Revenue is not used as evidence of good storytelling.
The Guardian: 4/5, published 8 September 2025. That publication’s score is separate from OtaHub’s.
So, is Infinity Castle worth watching?
Yes, if you already follow Demon Slayer and want to see its characters enter major confrontations. Familiarity makes their emotions easier to understand and gives you reasons to care about their pasts.
Newcomers should start with the preceding anime. If you prefer uninterrupted action and little explanation, consider the 155-minute runtime and the film’s repeated shifts between battles and flashbacks.
Strengths and weaknesses
Strengths
- The fights and changing castle are the main attractions.
- Confrontations connect with individual characters’ stories.
- The familiar composers and voice cast return.
Weaknesses
- Lengthy flashbacks repeatedly pause the action.
- Newcomers may struggle to understand the characters’ motivations.
- The war against Muzan remains unfinished.
OtaHub score
The total is the weighted average of the six anime criteria; editors may adjust it by up to ±0.2. See our review standards.
- Story & Script · 8.6Personal stakes give the confrontations weight, although the larger story remains unfinished.
- Characters & Voice Acting · 8.8Established motivations deepen the encounters, though flashback placement is less consistent.
- Animation & Visuals · 9.5The shifting castle supports ambitious action presentation without implying flawless execution.
- Music & Sound · 9.2The returning composers, theme performers and cast preserve the series’ identity.
- Direction, Pacing & Adaptation · 8.0Flashbacks add context but interrupt the progression of some fights.
- Impact & Rewatch Value · 8.4Existing fans benefit most; newcomers need the preceding anime.
OtaHub recommendation: Worth watching
How the total is calculated: the six criterion scores multiplied by their weights produce 8.77/10. Rounded to one decimal place, that is 8.8/10, in the Great band.
Frequently asked questions
Can newcomers watch Infinity Castle?
Yes, but the relationships and motivations will be harder to understand. Watching the anime through Hashira Training first is recommended.
Does this film finish Demon Slayer’s story?
No. It is the first of three films covering the final battle.
Why praise the film while criticising its flashbacks?
The battles and visuals are strengths. Revisiting the past adds character context but interrupts the action.
What is OtaHub’s Infinity Castle score?
8.8/10, in the Great band. It is the rounded weighted average of the six criteria in the scorecard.
Sources: Official staff and cast; Official music credits; Official streaming announcement; Official film website; The Guardian review; GamesRadar review.
