Few artists have become as closely associated with anime music over the decade and a half as Eir Aoi. Since her breakthrough with songs like “Memoria” (Fate/zero), “Innocence” (Sword Art Online), “Genesis” (Aldnoah.Zero), and “Hello Hello Hello” (A Couple of Cuckoos), she has helped define the sound of countless anime memories for fans around the world, pairing powerful vocals with stories that continue to resonate long after a series ends.

In April, Eir released a double tie-up single featuring “Unrealistic,” the opening theme for That Time I Got Reincarnated as a Slime Season 4, and “MONSTER,” the opening theme for Classroom of the Elite 4th Season: Second Year, First Semester. The release marked another milestone in a career that has taken her from anime newcomer to one of the medium’s most recognizable musical voices, performing everywhere from Nippon Budokan to stages across Europe, Asia, and North America.

We recently had the opportunity to speak with Eir about her fifteen-year journey in anime music, the challenge of writing for two very different series, the artists who inspired her own musical path, and what she hopes fans experience when one of her songs welcomes them into an anime world.

Twwk: You’ve become an enduring figure in anime through your musical contributions to anime series. With this upcoming double tie-up single, almost 15 years after the release of “Memoria,” how does it feel to continue to be a major figure in the anime space?

Eir: When I had just debuted, I was constantly afraid my career might end within just a few years. I didn’t have much experience, and being a singer was still completely unknown to me, so I always felt anxious.

Before I knew it, 15 years had passed. I’m truly grateful to be able to sing theme songs for anime, because when people watch an anime, even songs from over 10 years ago can be discovered or revisited through it. I feel very fortunate to be able to work in such an environment.

デビューしたばかりの時は、数年で藍井エイルが終わるかもしれないという恐怖に駆られていましたが、それは圧倒的に経験値が少なく、歌手というものが未知のものだったので、いつも不安に思ってました。気づけば15年経ってアニメのタイアップを歌わせていただくことは、誰かがそのアニメの作品を見た時に、たとえ10年以上前の楽曲だったとしてもアニメを見ることで過去の楽曲に触れてもらえるという非常に恵まれた環境で歌えることに感謝しています。

Your new song “Unrealistic,” was selected as the opening theme for That Time I Got Reincarnated as a Slime Season 4. Do you think it matches the series well? Have you watched any of the Tensura series?

I’ve been enjoying Tensura since the first season.

In this song and its music video, I aimed to express a very large-scale, expansive kind of rock sound. It features a strong, forward-driving melodic line and a cohesive band sound, and I feel these elements strongly connect with the world of Tensura.

The lyrics also revolve around the theme of justice and another justice, so I’d be happy if listeners paid attention to what justice really means while listening to the song.

転スラは第1期から楽しみに見ておりました。

今回歌わせていただいている「絵空事」はMVでも表現していますが、非常に広いスケール感でのロック　前に突き進んでいくような芯のあるメロディーライン、一体感のあるバンドサウンド、これらが転スラの世界観に強くリンクされている

歌詞も正義と亜正義がテーマになっていて、果たして正義とは何かというところにも注目して楽曲を聞いてくれたら嬉しいです。

Your new CD also includes “MONSTER,” the opening theme for Classroom of the Elite 4th Season: Second Year, First Semester. Classroom of the Elite is an intense and thoughtful series. What are your thoughts about your collaboration with this anime?

I’m very happy to have been involved in Classroom of the Elite this time.

Up until now, I haven’t had many opportunities to work with this kind of genre, so I was really excited when writing the lyrics.

When I first watched the series, I carefully observed what kind of person the protagonist Kiyotaka Ayanokoji is, and I found his cunning nature almost chilling. It was very enjoyable to write lyrics from that perspective. During the recording as well, I was conscious of singing in a way that conveys the story and Ayanokoji’s mysterious nature.

I’m very happy to have had this new experience.

今回よう実に、携わることができてとても嬉しく思ってます。

こういったジャンルの作品に今まで藍井エイルは関わらせていただくことは少なかったので歌詞を制作するときにワクワクが止まりませんでした。

最初に作品を見たときに、主人公　綾小路きよたかがどんな人物なのかを注意深く観察した後に狡猾さに戦慄して歌詞を書くのがとても楽しく、レコーディングでも物語や綾小路のミステリアスさを訴えかけるような歌を歌いたいと思い意識しながらレコーディングしました

新しい経験ができたことを嬉しく思っております。

One of my favorite artists is Tomiko Van—I’ve read that she inspired your music as well. Can you explain what influence she has had on your musical style?

Being drawn to Tomiko Van’s androgynous vocal tone was what first made me consciously aware of singing itself. It was also a moment that strongly influenced me. I think my desire to become a singer capable of expressing a similarly androgynous vocal quality was strongly influenced by Do As Infinity.

伴 さんの中性的な歌声に惹かれたことが私にとっての歌を意識するきっかけになり、

強く影響を受けた瞬間でもありました。

自分自身も中性的な歌声を扱える歌手になりたいと思ったのはDo as infinityさんが

強く影響していると思います。

Many fans around the world discover anime through its music. When you perform a song that becomes an opening theme, what do you hope viewers feel in those first moments before the episode begins?

I enjoy anime, and I’ve always felt that theme songs are something that bring a sense of excitement and anticipation.

I’ve long admired the idea of being able to deliver that same feeling to someone else through my own songs.

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From the production stage, I make sure to engage deeply with the work, and during recording I sing while visualizing the story and its content. I hope that even a little, this song can give listeners a feeling of excitement when they hear it and make them think of the anime itself.

今まで自分が、アニメ作品を楽しむ上でテーマソングはいつもワクワクする気持ちを与えてくれるものだと感じていました。

自分自身も同じ気持ちを自身の歌で誰かに届けられたらと憧れ続けていました。

制作から作品にしっかり向き合いレコーディングでは作品の内容をイメージして歌を歌い、少しでも作品を楽しんでくれる方にこの楽曲を聞いたら、アニメを思い出してワクワクするという気持ちを届けられたら良いなと思っています。

A final question for your American fans—do you have any plans to perform in the U.S. again?

I think the energy of live shows in the USA and the UK is really incredible!

I haven’t been able to come to the USA or the UK recently, but I will definitely be back again someday!

I can’t wait to see you all at the venue!

—

Please check out Eir’s website, streaming platforms, and social media links:

Official website (公式サイト)：https://aoieir.jp/
X（旧Twitter): https://x.com/eir_ruru2
Instagram：https://www.instagram.com/aoieir
TikTok：https://www.tiktok.com/@eir_ruru2?_r=1&_t=ZS-96vCoErIaKi
Facebook：https://www.facebook.com/aoieir
YouTube：http://youtube.com/@eir_ajito
Spotify：https://open.spotify.com/intl-ja/artist/18moNotPmBWa2YZtRnIoZ3

“MONSTER / unrealistic” streaming and download: https://lnk.to/LACM-24832s

Our thanks to Eir Aoi and her team for their time and for making this interview possible.