In the landscape of modern J-pop, few forces have reshaped the global trajectory of the genre quite like YOASOBI. Operating on the singular, defining premise of “turning novels into music,” the powerhouse duo – comprising producer Ayase and vocalist ikura – has spent the last seven years building a discography anchored entirely in storytelling. While traditional songwriters typically mine their own personal experiences, observations and imaginations for material, YOASOBI’s approach is rooted in fiction — they translate existing written works, including the contemporary novels, manga and short stories they love, into vibrant, multi-layered soundscapes.

This distinct methodology has yielded years of material compiled into THE BOOK series, a run of conceptual anthologies that has come to define the duo’s creative identity. Now, with the release of THE BOOK for,, YOASOBI officially closes the final chapter on this series. Spanning 12 tracks, the album’s final tracklist came together almost by accident, expanding as the duo repeatedly blew past their scheduled cut-off windows while a continuous stream of new hits poured out of the studio. For Ayase, the organic chaos of the project instantly resolved itself the moment their latest creation found its home. “When that last piece snapped perfectly into place as the first song, it really felt like the album came together beautifully,” he reflects, pointing to the structural weight of their opening track, “ORION” — their newest song born from their collaboration with Overwatch. Functioning as a reverse chronological timeline, the rest of the tracklist effortlessly unfurls like a rewinding tape of their boundary-pushing discography.

“These past seven years have been a journey we’ve walked hand-in-hand with ‘THE BOOK.’ Seeing a series we’ve poured so much love and deep personal attachment into come to an end definitely brings a wave of nostalgia and a bit of sadness.” – Ayase

This new album officially wraps up “THE BOOK” series. Looking back at this multi-year journey, how does it feel to close this chapter?

Ayase: These past seven years have been a journey we’ve walked hand-in-hand with THE BOOK. Seeing a series we’ve poured so much love and deep personal attachment into come to an end definitely brings a wave of nostalgia and a bit of sadness. But at the same time, we made this conscious choice because we want to take on entirely new challenges from here on out. We felt it was the right moment to put a full stop on this chapter for now. In that sense, it feels like a new starting line. It really makes me look forward to the stories we’ll weave next and the kind of albums we’ll create moving forward.

I read that you originally planned for this album to only have eight or nine tracks, but it grew into 12 because you had accumulated so much music since late 2023. How did you know when this specific tracklist was finally “complete”?

Ayase: We originally intended to release THE BOOK for, with just eight or nine songs, but we missed that specific timing window, and the project naturally expanded to this size. In a way, the tracklist felt complete at various stages, but then we’d drop another single and say, “Well, let’s include this one too,” and then the next one, until it grew into 12 tracks. Personally, I think there’s a beautiful symmetry in placing “ORION,” our newest song, as the opening track and having “Gekijou” close out the album. Even though the final track count was unexpected, once that last piece snapped perfectly into place at the very front of the album, everything came together beautifully. Since this marks the finale of the series, the larger tracklist actually lends the project a nice sense of drama.

If you had to pick one track on this album that surprised you the most during the writing or recording process, which one would it be and why?

ikura: Honestly, we pushed ourselves to try something completely unprecedented with every single track, so it’s incredibly hard to choose just one. But for me, “ORION” stands out. While some of our past songs featured fast-paced, rap-adjacent sections, this was the first time I tackled a proper, full-length rap delivery entirely in English. I took extra care preparing for that segment, focusing heavily on clear English pronunciation because we are extremely particular about the flow and feel of the rap. It was a completely new frontier for me and probably the biggest personal challenge I’ve faced recently.

Ayase: If we’re talking about pure surprise, I’d have to say “UNDEAD.” The song is tied to a franchise and a body of work that I deeply respect and love. Getting a brand-new short story written specifically for us to adapt into a song was an incredible surprise and honor in itself. But the real shock came after “UNDEAD” dropped — Nishio Isin-sensei went ahead and wrote an entirely new short story inspired just by me and ikura. That was completely insane, and easily the biggest surprise of the entire process.

In the early days, your roles were very clear-cut: Ayase writes, ikura sings. Now that you’re releasing THE BOOK for, how has that creative boundary evolved?

Ayase: Honestly, nothing has changed. That division has always remained very clearly defined for us.

“[For the Overwatch collaboration] I wanted the players to really feel the adrenaline, so I focused on how the music could heighten the in-game experience” – Ayase

What does a typical vocal recording session look like between you two?

Ayase: I’m incredibly meticulous when it comes to direction. I tend to be very detailed and particular about the nuances.

ikura: Despite that, the atmosphere in the studio is always really fun. Whether the concept of the song is heavy or it’s a quiet, emotional ballad, maintaining a positive environment is crucial for channeling the right energy into the performance, not just nailing the technical vocals. Everyone in the room helps foster that. When we hit a great take, the whole studio cheers along. Even during the challenging moments, there’s this unspoken wave of encouragement that keeps you going.

Usually, I’ll start by showing everyone my own interpretation of the track during warm-ups and initial monitor checks. From there, Ayase will provide direction using imagery, conceptual ideas or suggestions like, “What if we try approaching this line this way?” As we bounce ideas back and forth, we naturally sculpt the unique nuances and ultimate direction of the song together.

Your new track “ORION” is a massive global collaboration with Overwatch. How did this team-up happen, and did the creative process differ at all from your usual way of writing?

Ayase: I have to credit our amazing team for working hard behind the scenes to make it happen. They secured the opportunity because the game was implementing a new Tokyo-themed map. Since the team at Overwatch was building something centered around Japan, they specifically requested YOASOBI as their Japanese artist collaboration. We gladly accepted the offer, and everything flowed from there.

In terms of the actual songwriting, our foundational creative process remained exactly the same: an original story was written for us first, and then we constructed the music around that narrative. However, because Overwatch is a fast-paced FPS game, the internal mechanics required a different approach. I wanted the players to really feel the adrenaline, so I focused on how the music could heighten the in-game experience. Designing a soundscape that complements active gameplay and mirrors that intense sense of speed was a unique challenge that I hadn’t deeply explored before.

Between the two of you, who is actually the bigger gamer, and who would win an Overwatch 1v1 match?

[ikura gestures with both hands, pointing to Ayase]

Ayase: Let’s just say ikura-san isn’t exactly the most seasoned tactical gamer. Truly.

ikura: It’s true! I struggle when there’s intense time pressure, things chasing me, or in first-person shooters where split-second decisions dictate everything. But the game worlds look incredible, and I genuinely love being a spectator and watching others play.

From Pokémon and PlayStation’s 30th anniversary to Overwatch, you’ve built a brilliant relationship with gaming culture. What is it about video game worlds that translates so perfectly into the YOASOBI style?

Ayase: A big part of it stems from our deep cultural roots in animation, anime and manga — art forms that Japan is incredibly proud of. That creative background heavily influences everything we do. When you look at modern video games, the visuals, environments and character designs are essentially living 3D animations. These are fictional characters operating within expansive narratives, whether it’s high fantasy or intense sci-fi, with rich drama unfolding around them. In that sense, gaming is deeply intertwined with the storytelling DNA of anime and manga.

Throughout our seven-year history, YOASOBI has consistently collaborated with these narrative-driven mediums. So, transitioning into gaming felt entirely natural; the affinity was already there. Plus, both ikura and I are genuinely passionate about gaming culture — we love playing them and watching them. Ultimately, that’s why the connection feels so seamless: it comes from a place of genuine love.

“Moving forward, we want to thoughtfully deconstruct the legacy we’ve built so far to surprise our listeners.” – ikura

Now that THE BOOK series is officially wrapped, what can you tease about the next creative era of YOASOBI? Where are these “Never Ending Stories” heading next?

Ayase: Where are we heading next? That’s the big question. Closing the chapter on THE BOOK series stems from a mutual desire to step onto a path filled with things we haven’t experienced, things we don’t know yet and concepts we can’t even imagine right now. Truthfully, the slate is completely blank. The next major body of work will start taking shape once we’ve naturally gathered enough new musical pieces, so it’s likely a bit further down the road. We don’t have a rigid blueprint just yet.

That said, we have absolutely no intention of abandoning our core philosophy, which is to dive headfirst into whatever excites us in the moment. Whether it drops next year or the year after, the journey is going to evolve. I envision an album born from challenges that nobody expects — concepts that make even us sit back and think, “Wow, this is incredibly cool.” I want everyone to keep guessing, because we are just as eager to see where it goes.

ikura: Exactly. Over the past seven years, whether we’re in the studio tracking songs or out on stage performing live, our primary focus has always been to continuously push our boundaries and refuse to stagnate. Moving forward, we want to thoughtfully deconstruct the legacy we’ve built so far to surprise our listeners. We want to keep the community that loves YOASOBI on the edge of their seats, constantly wondering, “What could they possibly do next?” I really hope everyone is excited to step into this next chapter with us.