Kroi’s new song “SPIN” was written as the opener for the anime Steel Ball Run: JoJo’s Bizarre Adventure. A rousing melody and beat that evoke the American Old West, where the story is set, blend with Kroi’s signature chaotic funkiness, resulting in a highly original and exhilarating track. The song took off on streaming right after release, including the U.S. and debuted at No. 44 on Billboard’s Hot Rock & Alternative Songs chart (dated Oct. 10, 2026), the band’s first-ever entry on a Billboard U.S. chart.
Talking with the band revealed the relentless spirit of inquiry and creative urge behind it — an attempt to depict a new world no one has ever seen by digging into cultures closely tied to the band, from the anime song, a uniquely Japanese form of pop, to The Ventures, part of vocalist Leo Uchida’s roots. Drummer Hidetomo Masuda was unfortunately absent due to illness, but the remaining four members shared the story behind the making of “SPIN.”
Your new song “SPIN” is the opening theme for the anime Steel Ball Run: JoJo’s Bizarre Adventure. What does Steel Ball Run, and by extension the JoJo’s Bizarre Adventure series, mean to the members of Kroi?
Yuki Hasebe (Gt.): Of all the members, I’m the one who especially loves JoJo, and I’ve read quite a lot of it. Steel Ball Run was my favorite of them all. I’ve always been drawn to the Old West aesthetic, so pairing that with JoJo is, for me, a collaboration between two things I love. When we got the offer to do the opening theme this time, I was really happy and surprised.
Uchida: I hadn’t experienced JoJo yet, but it’s a series that people around me are deeply passionate about, so I’d been wanting to check it out someday. This was a good opportunity in that sense, too.
What did you feel after experiencing the world of JoJo?
Uchida: It really is amazing. It pulls you in. The works I love make me feel that there’s an atmosphere and a sensation you can’t experience unless you come back to them. JoJo is exactly that. There’s a feeling you can’t get unless you come back here. I was moved by how incredible that world-building is.
“SPIN” has elements reminiscent of Ennio Morricone’s film scores along with Kroi’s signature funkiness, making it a strikingly original song. What concept were you working from?
Uchida: The concept was something like, having no choice but to keep moving through a wilderness where you can’t see what’s ahead, still believing there’s a goal. There’s a goal in your heart that you want to move toward, but don’t know if it’s really the right direction. Still, you have no choice but to keep going. I think that feeling exists in Steel Ball Run, and it exists in the journey of making things, too.
You spoke of “a goal in your heart,” and the line “The frontier that still remains is within” really does give the sense of locating the goal you should aim for inside yourself.
Uchida: Right. When I write lyrics, for example, I can’t write with things brought in from the outside. I can only write with what’s inside me. So in the end, all I can do is dive down into myself.
Images of “wilderness” and “sand” have appeared in Kroi’s songs before, haven’t they?
Uchida: Yeah, it’s strange. We made a song called “Funky GUNSLINGER” a few years ago, and when we were studying up on things like that, thinking, “Let’s try writing a song with sandy terrain as its field” with no tie-in involved, we got an offer from a work with an Arabian flavor, then an offer from a work set in the desert, and this time an offer from a work set in the Old West. It feels like something is descending on us.
As a result, “SPIN” ended up with an extremely original sound, even within today’s Japanese music scene.
Uchida: There’s no one like this in Japan’s major-label music scene right now, with this kind of Morricone-esque feel. I also had an image of The Ventures in mind. The first band I was ever in was a Ventures cover band that an older guy I knew made me join when I was a kid. [Laughs] I played drums in it, so The Ventures are part of my foundation. A lot of people may associate The Ventures with surf music, but ever since I was a kid, I’d listen to songs like “Apache” and think, “This sounds like a Western.” I wanted Hasebe to take on a song with that kind of feel, and besides, a lot of people who play instruments in Japan have The Ventures in their foundation. The first thing I ever played on guitar was “Pipeline,” too. But there isn’t much music now that puts that front and center. So I also wanted to deliver that kind of thing to everyone once again.
Hasebe, Seki and Chiba, how did you approach the making of “SPIN”?
Hasebe: Within the ensemble, the guitar was in charge of evoking a deserted landscape, so I tried putting in a sound like a horse’s whinny and quoting memorable phrases from Morricone. There was a lot of room to mix in things I love, and it was a lot of fun.
You’ve sometimes performed live in Western-inspired outfits, and you’re quite fond of this kind of Western flavor, aren’t you?
Hasebe: Yeah. It’s a bit like Leo’s The Ventures anecdote just now, but sometimes you realize later on what you loved when you were little. When we made “Funky GUNSLINGER,” which came up a moment ago, I watched Western flicks to study them, but long before that, back in junior high, I loved Stevie Ray Vaughan. So it’s always been a good fit for me.
Seki, how about the bass?
Masanori Seki (Ba.): This time Yuki took on the role of expressing the Western feel and the world of Steel Ball Run, so I decided to keep a hi-fi quality in the sound and carry the power and momentum of an anime opener. Within that, though, I tried adding nuances like the sound of a horse’s hooves, so there were also parts where I was conscious of that sense of getting it right.
Chiba, what about the keyboards and the mix?
Daiki Chiba (Key.): What I prioritized on the keyboards was momentum. I remember it being hard to figure out the rhythmic phrasing, what kind of note placement would fit the beat and create momentum. As for the mix, the version that plays in the anime is my mix, but the one being released was mixed by someone else. We asked Nathan Boddy to do it. Our label boss suggested, “Do you want to try asking someone else to mix it?”
I see. Listening to “SPIN,” there’s a sense of scale, like a vast landscape opening up, and at the same time a claustrophobic chaos, like peering into an inner world. That chaotic feel really leaves an impression.
Uchida: This time I also wanted to face the peculiarity of the anime song, something that’s been built up over time within Japanese culture. Layers stacked on top of layers like this, fast-moving changes, and on top of that, it’s a vocal song. I don’t think you find music like this much outside Japan. I think it became the most chaotic song we’ve made recently, one that also carries that essence of the Japanese anime song. There were a lot of tracks, too. We brought back the horns at the very end, like, “Let’s put them in after all,” after cutting them at the demo stage, and the arpeggiator Masuda added is a nice touch as well. I think having that mechanical sound conveys that this song isn’t simply a recreation of a Western, but a story of a new world based on one.
“Not a recreation of a Western, but a story of a new world” is exactly what comes across when listening.
Uchida: We crammed in all kinds of things, each one of them has meaning, and the sum of them became a song that connects Kroi and Steel Ball Run. That’s how it feels. Part of what I came to love about JoJo is that “chaos.” The premise is fantasy, but because that chaos is there, people become entangled with one another, the story twists and winds, and the work as a whole becomes realistic. That strikes me as being very much like life itself. I hope we were able to express that in this song, too.
—This interview by Fumiaki Amano first appeared on Billboard Japan