For Kensuke Ushio, scoring Chainsaw Man – The Movie: Reze Arc was not simply a matter of creating intense tracks for action sequences. Instead, he approached the film as a study in emotional volatility — capturing the pull of a fleeting romance and the unease of a mysterious identity. At the heart of the film, Reze’s transformation from an unassuming, friendly presence into something far more dangerous pushed Ushio beyond his usual use of leitmotifs. In this interview, Ushio opens up about his detailed approach to the score, the challenge of expressing Reze’s “rebirth,” and how he leveraged dynamic surround sound to shape the film’s immersive soundscape.
This interview has been edited for clarity.
How did you approach composing the music for Chainsaw Man — The Movie: Reze Arc?
Kensuke Ushio: Reze Arc is, of course, [part] of the Chainsaw Man saga, and we already had a strong concept from Season 1. So, in some ways, this is a sequel to that. This is a movie, so we have tons of speakers in the theater. I tried to make something epic, with a big orchestra or a big bass sound.
Were there any notable differences when composing for Reze Arc compared to the TV series?
Kensuke Ushio: As I said, we have a lot of good speakers in the theater, so we have a dynamic range from a small sound to a big sound. If I compose for a TV series, I cannot do a real pianissimo, but in the theater, we can do that. That’s the difference between them.
How would you describe “Reze,” who represents the title character of this arc?
Kensuke Ushio: Ah, muse. Actually, for many of the Chainsaw Man characters, I’m really scared of them! They have some kind of conflict with demons, and I’m always a bit scared of Makima. But Reze [is different]. After she reveals her true self, she is also friendly. Like she says, “Hey, Denji-kun!” — and I feel like I can keep a relationship with Reze. She’s so lovely. She was a great muse for the inspiration of this film.
Did you receive any specific requests from the production staff?
Kensuke Ushio: Of course, they had a musical cue list. They wanted certain kinds of songs for this scene or that scene. After receiving that list, I had discussions where I could convey my thoughts to them. But the one request that was 100% theirs was Reze’s song in Russian.
You previously mentioned that the 2023 teaser for the film could have used either “into the pool” or the track “Reze,” but ultimately “Reze” was chosen because “into the pool” was considered too “deep” for a teaser. Could you share why these two tracks were considered candidates?
Kensuke Ushio: In 2023, we only had two tracks. It was in a really early stage, but what’s interesting is that after I read the pilot script and the character settings, those two tracks hit me. So, they became some kind of representation of the film. That was a very happy thing for me — serendipity, you know, it was a really good thing.
What did you seek to channel into the track “the city mouse and the country mouse?”
Kensuke Ushio: I always use a leitmotif — reusing another melody to arrange it for another scene. But when I composed this song, I tried applying the leitmotif from the first track, “first glance,” but it didn’t work because I thought this was a new Reze, a reborn Reze.
So, I composed a completely new track. Then, that new feeling is overpainted by Makima’s song, which was already published in Season 1. Those sequences really fit the end of this film, and after switching to Makima’s theme, a heavy bass [emerges], expressing something unknown, something deep. Maybe it’s the continuation to the next chapter. That’s the reason I composed that arrangement.
Please tell us about the creation of the “in the pool” track.
Kensuke Ushio: The first half of the film is very romantic and tender, so I wanted to express a feeling of love with “in the pool.” But there is always something behind a mask — a hidden feeling underneath. The melody itself is genuinely romantic, but the chord progression and the harmony reference 20th-century Soviet composers. I drew on that kind of cold, tsundere quality. After composing that romantic, melancholic piano, I sampled it and chopped it into a dance beat. That became the transition from the romantic part into the battle section. From there, the rhythm builds, the heavy pulse arrives, and it moves toward explosion.
The movie features a slower, romantic first half and a high-octane, action-packed second half. How did you view and take into account these two tones?
Kensuke Ushio: The first half is very romantic and touching. I wanted to express that feeling of love in “in the pool,” while keeping that behind-the-mask feeling. It has a very romantic melody, but the chord progression and the harmony really refer to 20th-century Soviet composers. I refer to that kind of cold, tsundere weather. After that, I composed a very melancholic piano sequence, then sampled it and chopped it to the dance beat. That became the transition from the romantic part to the battle part. After that, a heavy rhythm appears and builds toward the explosion sequence. That’s the total sequence of the film.
Back in 2024, I did a live set with Chainsaw Man and my tracks. In a dance music live set, I need to control the vibes. I don’t start with the peak track; I start with melancholic, small pianissimo piano and expand the feeling toward something more brutal, with the peak as the last sequence. The end is something more like a melancholic and sad movie. This is how I achieved the complete sequence of the movie, referring to my live experience with the Chainsaw Man performance in 2024.
What feelings would you like viewers to be left with after watching the movie?
Kensuke Ushio: I think Reze is a cause — people lost something. Everyone loses her. That sad feeling… [sighs] I feel it too.
Special thanks to Sony Music for the opportunity and for assisting with this interview.
Chainsaw Man — The Movie: Reze Arc is currently streaming on Crunchyroll. You can also listen to the original soundtrack here on music streaming platforms.
Questions by Melvyn Tan. Article written by Isabelle Lee.
