The June 2026 issue of Megami Magazine features singer-songwriter Aoi Eir in the magazine’s “Megami’s Voice” interview series. The artist is currently in the spotlight for performing two opening themes simultaneously: “MONSTER” for the TV anime Classroom of the Elite: 4th Season — Year 2, First Semester, and “絵空事” (Esoragoto) for the TV anime That Time I Got Reincarnated as a Slime Season 4.

First Impressions of Both Series

Aoi Eir shared her thoughts on both franchises. For Classroom of the Elite, she admitted that the protagonist initially seemed unremarkable, but was completely caught off guard when she realized he was actually the hidden mastermind — likening the experience to watching a suspense drama where you already know who the culprit is. She also praised the series’ exam arcs. For That Time I Got Reincarnated as a Slime, she appreciated how the cast of allies keeps growing with each season, and noted that Rimuru’s leadership style is almost instructional in terms of human relations.

Her favorite character in Classroom of the Elite is Karuizawa, joking that if she were a man she’d definitely fall for her — though she’d probably end up being strung along. In That Time I Got Reincarnated as a Slime, her top pick is Shizu, a tragic character who was summoned to another world, possessed by Ifrit, and met a sorrowful end — though Eir is grateful that Rimuru’s absorption of her allowed Shizu’s form to live on.

“MONSTER” — Ayanokoji Through Outside Eyes

“MONSTER” was selected through a competitive submission process, and Aoi Eir wrote the lyrics herself. She was drawn to the melody and the aggressive arrangement from the start, feeling it conveyed the excitement of finally seeing Ayanokoji at full power this season.

Since ZAQ, who handled the OP themes in previous seasons, had written from Ayanokoji’s own perspective, Eir wanted to try something different — depicting him through the eyes of those around him, and through her own. The title came naturally, as her very first impression of the character was that he was a “monster.” She noted this was a new creative challenge, as most of her tie-up songs had previously been written from a character’s point of view.

The B-melody section proved the most difficult to write. Feeling that all-Japanese lyrics wouldn’t fit, she searched for something that would, eventually landing on the English word “Hiding” — a perfect match for Ayanokoji’s habit of concealing his true abilities. The phrase ended up becoming the song’s central hook. She also incorporated the word “はみ出し” (sticking out / overflowing) in both the opening and closing lines, reflecting how Ayanokoji hides himself yet inevitably stands out.

Recording was not without its challenges. Eir disclosed that she had previously developed vocal polyps and a voice disorder from rock-style singing, which meant she had to work within certain limits. Despite this, she pushed through multiple takes to capture the cunning, calculating quality she wanted from the vocal performance.

“絵空事” — A Song That Comes Alive With the Crowd

“絵空事” was also chosen through a competition, with the final selection made by the production staff from two finalists. What sold Eir on the track was its call-and-response structure — a departure from her usual solo vocal style. She felt the song could only truly be completed with an audience, which resonated deeply with her.

The lyrics about “justice and ego” hit particularly close to home. She reflected on how many people online wield “justice” as a weapon, and whether what they call justice truly deserves that name — concluding that imposing one’s own values on others is never right.

Vocally, she aimed to convey a sense of confinement in the verse before opening up into the chorus, while balancing the rock energy of the track with the warm, expansive, and slightly sparkling atmosphere of the Tensura world.

Coupling Tracks: “DRUM” and “Decay”

• “DRUM” — A rock track with a contemporary Reiwa-era feel. Unusually, the chorus sits in a lower register and the song ends there, which was new territory for Eir. She sees it as introducing a new side of herself and is curious how listeners will receive it.
• “Decay” — A simple piano-based track that Eir specifically requested. The word “decay” resonates with her personally — she says she feels each day as a gradual fading, which motivates her to make the most of every moment. She hopes the song reaches people who feel like they don’t have a place in the world. Recording was emotionally demanding; she had the studio lights turned off to fully immerse herself in the song’s atmosphere.

A Single That “Has It All”

When asked how she’d describe the finished single, Eir called it “a rowdy one.” A double tie-up paired with two stylistically contrasting coupling tracks makes it both wild and well-rounded — a release that showcases both the familiar Aoi Eir and a newer side of her at the same time.

Looking ahead, she expressed a desire to create live shows that feel more like theatrical productions, blending her signature rock sound with fashion and performance elements. A live event, 『エイルの日～藍いスポーツ大会～』, has been announced for August 16 at Zepp Haneda (TOKYO).

Single Details: “MONSTER/絵空事”

The single is now on sale via Lantis in three editions:

• Artist Edition — includes “MONSTER,” “絵空事,” “DRUM,” and “Decay” / ¥2,750 (tax included)
• よう実 Edition — includes “MONSTER” and “Decay” / ¥1,980 (tax included)
• 転スラ Edition — includes “絵空事” and “DRUM” / ¥1,980 (tax included)

Artist Profile

Aoi Eir made her major-label debut in October 2011 with “MEMORIA,” the ending theme of the TV anime Fate/Zero. Since then, she has contributed to numerous anime soundtracks and continues to perform actively at live events both in Japan and abroad.