Singer-songwriter Aoi Eir, known for numerous anime theme songs, has released her first double tie-up single, “MONSTER / 絵空事.” The single features the opening theme for Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e 4th Season 2-nensei-hen 1st Term (“MONSTER”) and the opening theme for Tensei shitara Slime Datta Ken 4th Season (“絵空事”). In an interview for Megami Magazine’s “Megami’s Voice” series, Aoi shared her thoughts on the songs, the anime, and her creative process.
A “Rampaging” Single That Takes the Best of Both Worlds
—This single is a double tie-up. What were your impressions of each work?
Regarding Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e (hereafter YouJitsu), Aoi recalled being initially unsure about the protagonist because he seemed unremarkable, only to realize he was like a hidden boss. “It’s like watching a suspense story where you already know the culprit, and the various exams are very interesting,” she said. For Tensei shitara Slime Datta Ken (hereafter Tensura), she noted how the cast of allies keeps growing through the series. “Shizu’s story as a reincarnated person is poignant, and Rimuru uses his subordinates well—it’s an anime that teaches you about human relationships.”
—Which characters do you like from each work?
From YouJitsu, Aoi picked Karuizawa. “If I were a guy, I’d definitely fall for her. But I’d probably end up being toyed with.” For Tensura, her favorite is Shizu. “She’s a very sad character—summoned to another world, consumed by Ifrit, and meeting her end in battle. But I’m grateful that Rimuru devoured her and preserved her form.”
“MONSTER”: A New Perspective on Ayanokouji
—Both “MONSTER” and “絵空事” were chosen through competitions. What were your first impressions of “MONSTER”?
Aoi said she loved the melody and the aggressive arrangement. “It conveys the excitement of finally seeing Ayanokouji’s true abilities from this season onward.”
—You wrote the lyrics for “MONSTER” from the perspective of those around Ayanokouji. What prompted that?
Since previous OPs for the series were written by ZAQ from Ayanokouji’s point of view, Aoi wanted to try a different angle. “I depicted Ayanokouji as seen by others—and by me. From the start, he struck me as a ‘monster,’ so the title came naturally. Most of my tie-up songs have been from a character’s viewpoint, so this was a new challenge.”
—What points did you focus on in the lyrics?
She found the B melody particularly tricky to set words to. “I thought it wouldn’t work with all Japanese lyrics, so I searched for a fitting phrase and hit on ‘Hiding.’ Ayanokouji hides his abilities from everyone, so it matched perfectly. That phrase became the song’s hook.”
—The opening and closing lines are the same phrase—was that intentional?
“Yes. I considered what kind of monster to portray and came up with ‘hamidashi’ (sticking out) because he’s hidden yet conspicuous. Also, starting with ‘ha’ makes it easier to sing.”
—The song conveys Ayanokouji’s inscrutability.
Aoi remarked on his terrifying inhumanity. “But I hope there’s some kindness in him. Watching him interact with Karuizawa makes me feel sorry for her, yet he’s so matter-of-fact that I wonder if I’m the strange one. Personally, I think his attitude toward Karuizawa is horror (laughs).”
—What did you keep in mind while singing?
“The sound is intense, so I wanted a vocal that wouldn’t be overwhelmed. But because I’ve had polyps and vocal issues from rock singing, I had a limiter and couldn’t sing well at first. I wanted to maximize the cunning, so I did many takes. The song has very few breaths (laughs), so I consulted on where to breathe to achieve that sly expression.”
“絵空事”: A Song for Everyone
—What made you choose “絵空事” for the Tensura OP?
“We narrowed it down to two candidates and the staff decided. I felt this song could work with call-and-response. Most of my previous songs were solo performances, but this one comes together with everyone—that really struck me.”
—Which lyrics resonated with you?
“The lines about ‘justice and ego’ really hit home. There are many people online who wave their justice around, and I’ve wondered if that can truly be called justice. I don’t feel strongly about it now, but I believe we shouldn’t force our views on others. The song tackles that difficult theme.”
—What did you prioritize when singing “絵空事”?
“The A melody is sung in a closed space, then the chorus opens up—I wanted listeners to feel that sense of release. The tune is rock, so I growled where needed while also matching the work’s vibe of ‘good relationships with friends, vast and refreshing, with a bit of sparkle.’ This song is similar to my earlier style, with high notes, so it was easy for me to sing.”
Coupling Tracks: “DRUM” and “Decay”
—How did you approach the B-sides?
For “DRUM,” Aoi wanted a rock track with a Reiwa-era feel. “The chorus has a low pitch and ends abruptly. I’ve never sung that low before, so it shows a new side of me. It doesn’t sound like a typical anison, so I’m curious how people will receive it.”
For “Decay,” she requested a simple piano piece. “The word ‘decay’ means to rot. I feel like I’m decaying every day, which makes me want to live each day meaningfully. I think everyone has moments of feeling decayed or out of place, so I wrote lyrics hoping to reach those people. But ‘Decay’ was also hard to sing—the pitch and intonation pulled me away from the emotion. For the first time in a while, I darkened the studio to create an immersive environment before recording.”
A Single That Shows Both New and Old Aoi Eir
—What kind of single do you think this turned out to be?
“A rambunctious one. It’s a double tie-up with two very different coupling tracks. It’s rowdy yet takes the best of both worlds. I think listeners can feel both the new me and the me they’ve known.”
—This is your first release in a while. What activities do you want to pursue going forward?
“I want to keep doing rock, but also incorporate fashion-like elements to create shows that feel like performances.”
—A message for readers looking forward to the release?
“This is my first double tie-up. I sang to convey love while staying close to these beloved works. I hope that love reaches you. Please listen a lot.”
Profile
Aoi Eir made her major debut in October 2011 with the ending theme “MEMORIA” for TV anime Fate/Zero. Since then, she has performed many anime theme songs and continues active live performances both in Japan and overseas.
Information
On August 16, the event “Eiru no Hi ~Aoi Sports Taikai~” will be held at Zepp Haneda (TOKYO). For ticket details, check the official website: https://aoieir.jp/.
“MONSTER / 絵空事”
This single includes the OP theme “MONSTER” for Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e 4th Season 2-nensei-hen 1st Term and the OP theme “絵空事” for Tensei shitara Slime Datta Ken 4th Season. The Artist disc contains coupling tracks “DRUM” and “Decay”; the YouJitsu disc includes “Decay”; the Tensura disc includes “DRUM”.
Now on sale.
Lantis
Artist disc: 2,750 yen (tax incl.)
YouJitsu disc, Tensura disc: 1,980 yen each (tax incl.)
