Demon Slayer Movie: Infinity Castle Part 1 - Akaza's Return [SUB] (2025) Review

Demon Slayer Movie: Infinity Castle Part 1 - Akaza Returns [SUB] (2025) 6.5/10

[THIS WILL CONTAIN SPOILERS! READ AT YOUR OWN RISK!]

Hello everyone and welcome to another anime movie review. Today, I’m going to go over the first part of the trilogy finale of Demon Slayer. Infinity Castle Part 1 first aired in Japan on July 18, 2025, with the movie getting a US release on September 12. The movie is directed by Haruo Sotozaki, with Ufotable producing the film.

I have been hyped for this movie since it was announced last year. However, when I heard that it was going to be a trilogy of movies, my worries started to set in. I was worried that the producers were going to try and shove in too much content and mess up the story’s pacing. And that is exactly what happened here. As a story continuation, Infinity Castle Part 1 is fine, but as an actual movie, this is bloated and drags when it shouldn’t. Ultimately, this movie (and the rest of the films in production) should have been another season to allow the story to not only be told properly, but to allow the pacing to keep the viewer hooked. Let’s begin.

This movie takes place immediately after the end of season 4. The entire Demon Slayer Corp has been dropped into the Infinity Castle, where Muzan plans to eradicate every single one and eventually consume Nezuko so that he can have complete immortality. The movie will focus on three fights in particular while the rest of the cast are running towards their next fights. The fights are: Shinobu Kocho vs Upper Two Doma, Agatsuma Zenitsu vs Upper Six Kaigaku, and Kamado Tanjiro and Tomioka Giyu vs Upper Three Akaza.

As I said earlier, this really should have been a season. There’s too much going on here for this to be a proper movie. Hell, as I was watching this, this just felt like I was binging a season on the big screen. The previous movie, Mugen Train, was a movie because it was focused solely on the main villain Enma, with progression and storytelling replicating that of an actual movie. Infinity Castle is just too crowded, and the extensive length of the film doesn’t help with this. There were moments where I just wanted the movie to continue its main story instead of having numerous flashbacks (sometimes flashbacks within flashbacks). Was it nice to see Akaza’s backstory? Yes it was, but we didn’t need to be ripped away from the main story for 20+ minutes to see why he became a demon. And the film’s screenplay and editing didn’t help with this either. The movie should have more organically woven in Akaza and Shinobu’s backstories instead of hamfisting it in the middle of their battles. The whole thing with Zenitsu was fine, but still felt out of place because Akaza was the main focus of the movie

As for the fights themselves, they were dope thanks to both the animation and excellent storyboarding. Rest in peace Shinobu. She did not deserve to go out like that. Unfortunately I was spoiled years ago about her death, so it didn’t hit me as hard as it should have. It still sucks and I am curious to see how Kanao deals with Doma. The fight itself was cool as we got to see Shinobu go all out, but because of her poison, she was unable to do anything against him. Zenitsu vs Kaigaku was a very unexpected surprise. Seeing an Upper Demon using breath stances was very interesting (and a nice set up for that other demon who looks like he’s part of Tanjiro’s lineage). The best part of this fight was seeing Zenitsu get serious without needing to fall asleep. Bro was straight to business with absolutely no mercy.

And of course we have the main battle: Tanjiro and Giyu vs Akaza. First let me just say it was awesome seeing Giyu in the fold again. The last time we saw him do anything was back on the spider mountain. I know Hashira are strong, but I was not expecting him to be able to go toe-to-toe with Akaza. The fight was well paced (minus the flashbacks) and it was really cool to see Giyu spawn a mark as well as Tanjiro essentially enter Ultra Instinct lol. I know it’s not Ultra Instinct, but it basically was with the way it was described. The entire fight was well rounded and showed just how much of a monster Akaza was. Of course we saw that with his fight with Rengoku, but seeing him go all out against 2 Hashiras (I’m counting Tanjiro as a Hashira as Giyu said he is as strong as one now) was really cool. I will say, Akaza getting up after his head disappeared was fucking bullshit. I expect Muzan to survive a fatal blow like that as that is already expected, but Akaza? Nah that’s bullshit. Him surviving felt like a way to pan out the movie and show off his backstory, which should have been shown before the fight started. Regardless, it was nice to see him “give up the will to live”, which gave Tanjiro the win. Even Akaza was like “Tanjiro got me. I lost. Let me die.” Overall, the story is fine, but its execution could have been handled a lot better. 

As for sound design and music, the movie did not disappoint. Well I guess it disappointed just a little bit. Sound design was awesome as I had not seen a movie in a movie theater since Superman. That surround sound was dope, especially with Zenitsu and his lighting. Music was good. I especially liked all the stuff with Akaza, but for the Opening and End Credits song, completely forgettable.

The Japanese dub still hits hard. Best performances go to Natsuki Hanae (Tanjiro), Hiro Shimono (Zenitsu), Saori Hayami (Shinobu), Takahiro Sakurai (Giyu), Akira Ishida (Akaza), and Mamoru Miyano (Doma).

I’ll say it again. Infinity Castle is a decent continuation of the story, but this should NOT have been a movie. It’s too cramped, drags at certain parts, and overall just does not feel like a movie. This would have been much better as a season to cover not only this first part, but the rest of Infinity Castle and the epilogue. I’m still a bit excited with Part 2 whenever that gets released, but I do have my reservations. Until my next review, stay frosty and watch out for demons.

Thanks for reading.

        This is Zorgak, signing off.