[Interview] Aimer × LiSA Talk About "Songs" and "Oshi" as They Journey Through Demon Slayer Together – Double Theme Songs in the "Infinity Castle Arc"

　In the film Demon Slayer: Infinity Castle Arc – Part 1: Akaza Returns, released on July 18, Aimer and LiSA perform the double theme songs. Having each brought color to different arcs of the series, the two now come together through the theme songs in this latest installment. We spoke with them about their thoughts on the collaboration — and their Oshi (favorite character)．

■ We Never Thought We’d Be Involved Together at This Timing

— In the film Demon Slayer: Infinity Castle Arc – Part 1: Akaza Returns, Aimer’s “Taiyō ga Noboranai Sekai (A World Where the Sun Never Rises)” and LiSA’s “Zankokuna Yoru ni Kagayake (Shine in the Cruel Night)” were chosen as the theme songs. How did you feel when you first heard the news?

Aimer:
I honestly didn’t expect to be involved with Demon Slayer again, so I was really surprised—and deeply honored. LiSA and I debuted around the same time and have each been forging our own paths, so I was truly happy to be working together like this.

LiSA:
I was just so happy to be able to return to Demon Slayer through my music. Being welcomed back into this world was incredibly meaningful. I was also thrilled to be collaborating with Yuki Kajiura again. And when I heard that Aimer would be working with Go Shiina, I thought, “It’s like an all-out battle, just like in the story.” It felt like everyone was coming together for this, which made the whole experience so exciting.

— What did you think when you listened to each other’s songs?

Aimer:
The development was incredibly intense, the contrast was powerful—I was blown away. Her voice still has that unmistakable connection to her past works, but this time it’s mixed with an even denser and richer world. After watching the film, everything clicked. I realized how perfectly the music was crafted to match the visuals—it only truly hit me once I saw it in theaters.

LiSA:
When I heard that Aimer would be working with Go Shiina, I kept wondering, “What kind of approach will they take?” And when I finally listened to it, just like Aimer said, I was amazed at how beautifully the music and visuals enhanced each other. It was truly impressive.

— Once again, what do you find most captivating about each other as vocalists?

Aimer:
There are so many amazing things about LiSA, but what really stands out is how clear and pure her tone and resonance are. It’s the complete opposite of my own voice. No matter how much I try to create a clear tone, there’s always a slight cloudiness to it. But LiSA’s voice is truly crystal-clear—like it’s 100% pure.

LiSA:
Aimer is incredibly skilled at “coloring” her voice. She controls her tone in a way only a human could—changing her breath and nuance with each phrase. It’s a form of expression that only a person can achieve. I think she’s an artist with a truly one-of-a-kind voice and expressive power.

■ Demon Slayer takes me to places I’ve never been before

— What does Demon Slayer mean to you both? Have you ever felt pressure being involved with it?

Aimer:
When I worked on “Zankyosanka” and “Asa ga kuru,” I approached it with the mindset that I had to match the energy of the series and the passion of the fans. Thinking about how LiSA sang “Gurenge” under that kind of immense pressure, I truly admire her. It’s incredible.

LiSA:
When I was working on “Gurenge” and “from the edge,” I felt like I was running alongside the series. It kept expanding, taking me to places I’d never been before. Every day felt like a challenge into the unknown. There were moments of confusion because it was all so new, but it was an absolutely amazing experience, and it’s what brought me to where I am today.

— You’ll be celebrating your 15th debut anniversary next year. As a vocalist, how do you take care of your body and voice?

LiSA:
It's honestly really tough! (laughs) But recently, I feel like I’ve finally started to understand my body and how to manage it. I used to think I could push through anything with pure willpower, but that didn’t always work. After going through many cycles of trying and failing, I think I’ve come to know my own limits.

— Aimer, is there anything you’re particularly mindful of when it comes to caring for your voice and body?

Aimer:
For me, it’s really important to start singing very gently and ease into it gradually. With this song too, I didn’t go full power from the beginning—I built up the intensity slowly. I believe that by “singing gently, gently,” I’m able to express things even more powerfully.

— What was it like working with Go Shiina and Yuki Kajiura this time?

Aimer:
This was actually my first time meeting Go Shiina. The first demo I received was incredibly impactful and dense—it made me wonder whether I could fully express everything it held. The song was structured in a way that required the full range of my vocal register, so it was certainly a challenge. But I focused deeply on how to use dynamics and vocal tone, and I think I was able to record it successfully.

LiSA:
I’ve worked with Yuki Kajiura several times on past songs, so this time, I visited her studio and shared my thoughts and feelings with her directly. She then adjusted the melody of the chorus to what it is now, based on that conversation. I’m really grateful for that.

■ The Two’s ”Oshi”

— After watching the new film, were there any characters who particularly stood out to you?

Aimer:
Akaza, for sure—and also Zenitsu. I was really moved by this new side of Zenitsu we saw. Throughout the whole film, there were so many scenes that were just emotionally overwhelming… I don’t think anyone could watch it without a handkerchief.

LiSA:
I think it’s still Shinobu Kocho… maybe? But honestly, I keep finding more and more characters I love—even among the demons.

— Lastly, please share your thoughts on the theme songs once again.

LiSA:
It’s a song with so many developments. Every section feels like it has its own “Oshi” melody, and the whole piece is packed with excitement from start to finish. The frequent changes in structure almost ”carry you away”, so I hope listeners will enjoy not just the song, but the emotional ups and downs alongside the world of the film.

Aimer:
I poured a sense of strength into the song—something that conveys resolve, even within feelings of anxiety or urgency. When you listen to the full version, I think you’ll feel the emotional contrast and intensity even more. There’s a part where the instrumental drops out, and we adjusted it with extreme care to find the right balance of how eerie it should feel. I’d love for people to really take in those subtle moments as well.

【LiSA】
　Born in Gifu Prefecture. She has performed theme songs for numerous popular anime, including the Demon Slayer series, earning acclaim both in Japan and internationally. In March 2025, she released her 23rd single, “ReawakeR (feat. Felix of Stray Kids),” and in June, held her first North American tour. Known for her powerful performances and positive messages, she continues to break new ground. In the film Demon Slayer: Infinity Castle Arc – Part 1: Akaza Returns, released July 18, she performs the theme song “Zankokuna Yoru ni Kagayake (Shine in the Cruel Night).”

【Aimer】
　Made her major debut in September 2011 with the single “Rokutouseino Yoru” In September 2016, she released her 4th album "daydream", which includes her signature song “Chouchou Musubi” The album topped various digital charts and received the Runner-up Grand Prize at the CD Shop Awards 2017. In 2021, she performed both the opening and ending themes—“Zankyosanka” and “Asa ga kuru”—for the Demon Slayer: Entertainment District Arc anime. In the film Demon Slayer: Infinity Castle Arc – Part 1: Akaza Returns, released July 18, she performs the theme song “Taiyō ga Noboranai Sekai (A World Where the Sun Never Rises).”

Source : ORICON NEWS