Kenshi Yonezu/Hachi - IRIS OUT / JANE DOE & 1991

WIRED, October 16th, 2025 (Original Article)

Kenshi Yonezu Speaks on the "New Fireworks" That Spark Between the Self and Others

Recently, Kenshi Yonezu has announced numerous tie-ins and collaborations in succession, including inviting Hikaru Utada to sing for the ending theme of the Chainsaw Man: Reze Arc movie. We spoke about just what stimulates him, and the wellspring of his overflowing impulses.

IRIS OUT, theme song for the Chainsaw Man: Reze Arc movie; JANE DOE, the ending theme for that same film with Hikaru Utada on vocals; and finally, "1991," the theme song for the live-action film 5 Centimeters Per Second directed by Yoshiyuki Okuyama. This fall, Kenshi Yonezu released three songs made for films one after another.

Kenshi Yonezu could be considered an extremely busy artist in the past few years. While doing tours both within and outside of Japan, last year he released the album LOST CORNER. During that time, he worked on numerous theme songs: Globe for Hayao Miyazaki's animated film "How Do You Live?" [The Boy and the Heron], Plazma for Mobile Suit Gundam GQuuuuuuX, and "Bye Now, See You Someday!" for the NHK morning serial Tiger With Wings. This is in addition to use of his songs for commercials, such as LADY, made for a Coca Cola Japan Georgia commercial, and RED OUT, used in a Spotify brand commercial; the highlights of his career are almost too numerous to count.

Why has Kenshi Yonezu unhesitatingly continued to work on so many tie-ins and collaborations? As can be gleaned from his past remark that "through collabs, I get a sense of being raised as a member of society," he considers "others," the artists and stories that exist outside his own world, to be his point of contact with society.

Which is exactly why he can't fear sociality. He continues to search for new "fireworks" that spark between himself as a musician and the world. The sharp words he's able to produce via his cooperation with Chainsaw Man: Reze Arc, Hikaru Utada, and Yoshiyuki Okuyama speak more than anything to his way of life as a musician.

— The recently-released IRIS OUT and JANE DOE are the theme song and ending song respectively for the Chainsaw Man: Reze Arc movie. What sort of direction did you get from Director Tatsuya Yoshihara and the production side?

When I made the proposal for what I wanted to do while talking with the director and MAPPA production team, they accepted me doing both the theme song and ending, saying "we leave the approach to you, Yonezu-san." Of course, there were naturally small adjustments made such as to match lengths to the film, but for both IRIS OUT and JANE DOE, thanks to them fully putting their trust in me, I was allowed an extreme level of freedom in creating them.

— So production was generally smooth, then.

I'd like to say that, but... it did run a bit behind schedule. I planned to work on it starting around the middle of last year toward the end of the year, and have a demo mostly completed before starting my world tour this year ("JUNK"), but it didn't go that smoothly.

When creating songs, I "shut myself" in my own world, and condense down a lot of different things. Meanwhile, at concerts, I spread out the things I've condensed within me for the listeners. It's very difficult for me to come and go across the gap between those modes.

— Let me ask about your methodology there. When you're doing a song for an anime or the like that's based on a manga, that "story" exists as a precedent. How do you align your creation process to match with that sort of inherent constraint?

Even if I say I was allowed to do as I pleased, of course I centered my thoughts around the work as a whole. Chainsaw Man's general style, and the overall picture of the story in which Denji is tossed around by a woman named Reze, served as the base for these two songs.

— Besides the tone and construction of the song, the title "IRIS OUT" also symbolizes that overall picture. I assume it's taken from the term for a screen transition in which a shrinking circle turns the screen black?

It was a common sight in older anime; the iris-out was often used to tie up a bad ending in a comical way. I felt that nuance suited the story very well. Denji's field of view very rapidly shrinks after falling in love with Reze, so I thought it could connect with the nature of the protagonist.

— The title of the ending theme, "JANE DOE," is used in English to indicate "a nameless woman," or "an unidentified female corpse." What were your intentions behind choosing this term?

The thing that become an axis of the song right at the start was the lyrics for the chorus - the imagery of walking on shattered glass shards barefoot, bleeding from your wounded soles, and leaving red footprints that continue into the distance. Reze is a character with a mysterious and unknowable side, so I imagine she's erased all sorts of traces of her. Though she's left somewhere afar, her red footprints will always remain... I had that imagery as my central axis. Around then, I made a mental association with the phrase "John Doe" (indicating an unidentified male corpse) which I learned from David Fincher's movie Se7en, and incorporated that into the title.

— For the 2022 Chainsaw Man TV series as well, you wrote the opening theme KICK BACK. Were you conscious of a contextual link with the previous work?

They're both Chainsaw Man, so there's inevitably a connection whether I'm conscious of it or not. Thus, I didn't intentionally try to create a sense of connection. Rather, I would say I was thinking more about how I could differentiate them with my way of expression.

— In past interviews, you've referenced the fact that for collaboration songs, you align yourself with "another," namely the work or its story, always thinking about what you have in common and the halation produced by the boundary between you. What sort of mental state are you usually in for that brain-racking process?

When I'm working on theme songs or ending songs, I'm always feeling my distance from the project itself. For example, if it's a song that plays during the work, I'm in close contact with the production team, carefully matching it to durations and the script. In the case of theme songs, it's something that "sits on top of" the work, so to speak; there's a fixed distance.

As consequence, it feels like I'm standing at the furthest point from the production. Though of course, it depends on how I'm making it as well. However, depending on the timing for when it goes public via previews or advertisements, things may flip around such that the theme song stands in front.

While I'm making something, I always have a strong feeling of "I wonder if this is actually okay?" I'm given quite a lot of freedom, but because of that, I'm anxious every time about whether the thing I freely made by myself is really the thing that's suited for the story.

— So it's still like that for you even now. That's very surprising.

If it seems to get a good reception upon release, I'm relieved, like "ahh, thank goodness." It just cycles that way over and over. Although if it's not music I'm constructing on top of a story someone else created, but a song where all my own senses are permitted, I suppose I don't have those worries as much.

But here, the story of Chainsaw Man precedes me. The original creator Tatsuki Fujimoto-san and the director should be the ones to stand in front, so it'd be wrong to push through something that doesn't suit the story; doing that wouldn't make anyone happy.

That being said, I also don't want to make something so unobjectionable as to be boring. Figuring out the right level of seasoning is something I struggle with every time.

— JANE DOE is also a collaboration with Hikaru Utada-san for the vocals. What sort of process did you go through to accomplish this?

We have actually met once before due to having some acquaintances in common. But at the time, I wouldn't have even dreamed they'd someday be involved with one of my own songs.

However, I did have an awareness from the start that someone other than myself should sing the ending song for this story centered around the woman named Reze. While putting together the piano intro riffs and first verse, solidifying what direction to go in, I started to think "it could only be Utada-san."

— Why was that?

They have a variety of songs, so I don't want to speak unconditionally, but my personal impression of Utada-san is, they have a very melancholic air about them that squeezes your heart with pain and lonesomeness, while also having a great husky voice with a kind of dry eloquence like the wind blowing. I can sense that kind of duality.

In addition, after you listen to such wonderful songs produced by such a massive talent, it might even make me feel "do they even really exist?" Speaking as a simple listener, being such a massive and distant presence actually gives them a kind of faintness; you get the feeling like they might disappear the moment you look away.

That duality and tenuousness of presence linked in my mind to my impression of Reze. So I decided I might as well give it a shot and ask.

— From the standpoint of a common listener, I can certainly agree with that feeling of "do they really exist?" How did it feel to get the OK from such a figure?

I was just plain happy. On the other hand, having a great musician I'd listened to since I was a kid, who with immense musical talent writes and sings their own music, sing my song... it made me rather nervous.

— Utada-san made this comment on JANE DOE: "As fellow songwriters seeking to represent themselves, we pushed forward figuring out what things we could understand in one another better than anyone, and what things contrasted in our methods of expression." You'd have to ask Utada-san to know what they truly meant, but Yonezu-san, what did you feel you "understood in one another"?

First things first, there's the fact that both of us wanted to be manga artists when we were kids. In the conversation we had continuing from that, I learned that Utada-san had also been a kid who read a lot of books, turned their mind inward, and greatly valued fantasies and imaginary worlds in their head. I tended to seclude myself in inner worlds too, so I felt a great amount of empathy.

— Getting to work together, what was your view of Utada-san as a musician like?

I really like Utada-san's sense for words. While there are many parts of their lyrics and interviews I empathize with, looking from there toward their thoughts, I figured they're someone who's lived with a strong rationality.

Utada-san's words almost carry the air of a philosopher. You can sense the rationally-acquired sensibilities oozing from their words. Always confronting things that they're unable to cope with in life, seeking the best compromises to coexist with them... I felt that Utada-san must be a person who's thought about that stuff a ton, especially as I actually talked with them. Of course, that's only my guess, but if that is the case, I'm exactly the same way.

— Utada-san's comment also mentioned "things that contrasted in our methods of expression." What aspects did you sense differed between you?

One major thing I felt to be different was that Utada-san has a strong R&B influence at their roots. Meanwhile, my roots are in digital music - I come from rock, alternative rock, and Vocaloid.

To give an example, when Utada-san sings, they're very freeform with the rhythm and do it in a laid-back style [ED: a singing style in which you intentionally delay the song's rhythm], but I have a strong digital music background, so I can be extremely focused on the vertical grid lines. Still, you might consider this to be highly effective for this song's concept.

— In what way was it effective?

The first thing I told Utada-san to convey my picture of the song was "it's a duet between a girl who's dealing with all manner of complicated things, and a boy who fundamentally doesn't understand any of that." Considering this, those musical differences, that sort of mismatchedness, fit in the song very nicely.

— On October 13th, you also released "1991," the theme song for the live-action film 5 Centimeters Per Second directed by Yoshiyuki Okuyama. You've stated that this song "ended up as something looking back on my own life thus far." Could you tell us what you meant by this?

I saw the original version of this movie, the animated film directed by Makoto Shinkai, when I was in high school. As someone living a gloomy existence despite my youth, it pierced me right through. I bought the novelization too, took it with me on a field trip, and read it by myself in the corner of the shared room at the inn while my classmates had fun with each other. I was that kind of kid.

I was shown a rough cut of the film to make the song, and seeing Takaki played by Hokuto Matsumura-san, it really felt like I was looking at myself. His slightest behaviors, the harsh criticisms directed at him, I felt them passing through the screen and piercing my heart. At the same time, it was a film filled with Okuyama-san's immense passion, so if I was going to do a song for this movie, I thought, I had no option but to look back on my own life.

— Since the work was so strongly connected to memories from your childhood.

I met Okuyama-san a few years ago as a director of music videos; this 5 Centimeters Per Second was his first time directing a long-form commercial movie, and he came to me to discuss a music offer. You could certainly just call it chance, but at times I thought, maybe this was something that had been decided in advance long in the past.

— In the past few years, you've been doing all sorts of collaborations, with Utada-san, Studio Ghibli, Studio Khara. So although you've been doing successive collaborations you likely wouldn't have even dreamed you'd get to do, something about your cooperation with Okuyama-san felt particularly fated.

This sort of thing just makes me think for a moment, maybe it was all decided from the start. It feels like I'm being guided by a single gleaming thread... What exactly is going on here? Where did that thread come from? Even if I look back with a wholly logical perspective, it feels like that thread goes back to a very long time ago.

— These three songs included, you've worked on a large number of tie-ins and collaborations over time. What stands out to me is how, in line with your remark of "through collabs, I get a sense of being raised as a member of society," you treat them as your point of contact with society. Generally, the desire to self-express through works of art and the commercial needs of collaborations produce a degree of mental conflict. However, in your case, you feel as if it gives you a stronger awareness of things external to you - society, other people, stories, words, thoughts. How do you think of the balance between sociality and being a creator?

I was born and raised in Tokushima prefecture, but if I didn't have an aptitude for music, and didn't have luck on my side either, such that I just stayed there, I might have been forced to live with the awareness of being a faulty person. I really think so.

That's just how strongly I've felt I was socially lacking, ever since I was a kid. I'm really bad at conversing, and seeing classmates talking to each other excitedly felt like watching a battle between Super Saiyans. Things that were ordinary for those around me, I simply couldn't comprehend; I often felt like they were events from another world.

For someone like me to live in the world as a human, I had to introspectively look at every little thing in great detail, asking "why am I this way?" As I went on doing this through music, I ended up feeling strongly that manifesting in that way gave me a connection to the outside world.

Thinking back on my childhood, there were a lot of things about me you could broadly call "a creator's sensibilities" - a lack of sociability, being different from other people. Which is why, paradoxically, I become so attached to sociality.

— Am I right in thinking you see that positively?

I see it as an extreme positive. The world of creation is one where being an carefree figure detached from society can be a weapon, and it can also be an indulgence. However, sometimes I think of that as terribly ugly, or frankly wretched.

In life, there are all kinds of complicated elements and confusing procedures, so you can't possibly live without having connections to others. And it inevitably becomes necessary to make compromises with the people in front of you, with society. Could one manage to live fully ignoring that? I wonder.

Supposing you are someone who's lived without being conscious of that at all, there must surely be people out there who pay that price instead. And what should one think about those people?

I think about these things because I can innately feel the incredibly low probability by which I've arrived at my current position. To put it artlessly, "I want to be a kind person." (laughs) I'm filled with those feelings.

— Technology is one pillar of society, or could even be called sociality itself. 2025 has been a year in which a technology that could be a major turning point for humans, artificial intelligence (AI), has spread explosively; how do you perceive that technology as a musician?

Regarding AI, you can't avoid looking at it as a musician. I also often think, "seems the time has come."

— What do you mean by "the time has come"?

I mean that the time might be coming that people have to wake up to the fact that "intelligence" has always been a concept with a very narrow view, one extremely tailored to humans' convenience. This might sound sudden, but...

I have a particular fondness for Japanese horror. And thinking about why ghosts are scary, it's because our measurements of morals, ethics, and science don't apply to them at all. And entities like that are doggedly coming to hurt you. You don't even know why they're trying to cause harm. I think that "unknowableness" is at the root of scariness.

— I see. And you're saying that's not just something that applies to ghosts.

That's right. In daily life, the person in front of you could suddenly pull out a knife and stab you... Since you have no guarantee something like that won't happen, within each and every person resides that ghost-like "unknowableness."

I could say the same thing about myself. As much as I try to rationally control my senses and emotions, I can still take puzzling actions that contradict that. AI is also that sort of entity under our current measurements, and so is society.

Nevertheless, the thing that can oppose that unknowableness is reason, right? Even with ghosts, if you're able to understand who they were in life and their background, their scariness might change into cuteness or heartfelt sadness. Understanding things rationally is how you confront the unknown.

We can pit reason against the ghost-like things we keep inside us. The sparking fireworks that result from their collision might be referred to as the "sense of wonder."

— Looking at it that way, there are fireworks sparking between technology, society, and people as we speak. And because you're thinking of the new senses that can come from it, you don't fear pursuing sociality, nor technology.

Speaking of technology, this is something I talked about with Fujimoto-san (the original author of Chainsaw Man), but I think we live under the blessing of technology, and it's why we have our present.

Fujimoto-san draws manga digitally, and I've made music digitally. Until just a bit ago, ours was a world where music required a eye-popping amount of money. Yet it's been rapidly democratized by digital tools, such that people on the street like me can start doing music.

— The tour you're starting next year is also named "GHOST." Sure enough, I suppose it has that context to it?

To be honest, I wasn't considering that at all; I can only say it's a coincidence. But when talking like this, I make connections, like "well huh, maybe it is like that." This kind of thing honestly happens pretty often. (laughs)

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