The Creators Behind ‘Mechanical Arms’ on Conveying the Essence of the Anime Series Through Its Songs: Interview

On Oct. 4, the digital maxi-single VORTEX was released. This single, which contains three songs, features vocalist Setsuko of Kuhaku Gokko.

The songs “VORTEX” and “karma” are the opening and ending themes of the TV anime series Mechanical Arms. In the show, protagonist Hikaru Amatsuga meets Alma, a mechanical life-form shaped like an arm, and becomes embroiled in a series of incidents. Billboard Japan spoke with Setsuko, Okamoto (the original planner and director of Mechanical Arms), and Hiroyuki Sawano (the songs’ composer, arranger, and producer) about their impressions of “VORTEX” and “karma” and the creation of these songs.

Setsuko and Hiroyuki, what are your impressions of each other’s music? What kinds of things did you think about during your musical collaboration?

Setsuko (Kuhaku Gokko): When it comes to Hiroyuki, I’ve listened to his work as SawanoHiroyuki[nZk] more than his soundtrack work. [nZk]’s songs have the same musical foundation, but the impression they make changes a lot depending on the vocalist. I feel like that’s because when he writes the music, he makes space for the vocals. So then the question becomes, what should I do in that space set aside for me? To be honest, I wasn’t feeling very confident when he first reached out to me.

Hiroyuki Sawano: My impression of Kuhaku Gokko, which Setsuko’s a member of, is that their sound has an edge to it. “VORTEX,” (the anime’s opening theme song) in particular, has a rock-like rhythm, so I was looking forward to see how Setsuko would express herself. I’m more interested in how vocalists’ voices will sound within my songs than in the sound of the vocalists’ voices themselves. In that sense, I was dealing with the unknown, but that’s part of what makes it interesting.

Okamoto, you’re the original planner and director of Mechanical Arms. What were your expectations for the collaboration between Setsuko and Hiroyuki?

Okamoto: I was hoping that with the opening theme, they’d make something that depicted the work at the surface level, and with the ending theme, they’d delve deeper inside it. I’ve listened to Hiroyuki’s music before, in my everyday life, but I’m embarrassed to admit that I didn’t know much about Setsuko’s Kuhaku Gokko project. But precisely because of that, I was really looking forward to hearing what kind of world the two would create when they combined their musical sensibilities. Both the opening and the ending themes far surpassed my expectations. I feel like they’ve expressed things that we weren’t even able to express in the anime’s art and scenarios.

Hiroyuki, you said that there were rock elements to “VORTEX,” the opening theme. To me, it feels more like dance music. It feels to me like you tried to give it a straightforward feel.

Sawano: It has a dance music-like groove, as you said, and I also tried to mix in some rock and electro elements. Depending on how you look at it, this anime has parts that can be seen as comical, but I feel like the real highlights are the stylish battle scenes. I wanted to express that coolness in the sound of the song.

Setsuko: My first impression when I heard the demo was also that it was simple and cool. That came as a big surprise. What I mean by that is that my own impression of Mechanical Arms was that it’s a very comical anime. Of course, the battle scenes are really stylish, but the everyday scenes have a comedic pace to them, and there’s a certain cuteness to the shapes of the mechanical elements and way people move. So my overall impression was pretty much the same as Hiroyuki’s. I didn’t expect the music to be so solid, so I was like, “What kind of vocals should I be adding to this?”

The instrumentals in “VORTEX” are straightforward and a little inorganic, but your vocals, Setsuko, passionately wind through the song. I think the elements are incredibly well-balanced.

Sawano: I wanted the vocals to have a bit of heat to them, a bit of energy. But it’s not like I was initially trying to go for a gap between the heat of the vocals and the coolness of the music. That was just the result of leaving the singing up to Setsuko. She’s the one responsible for creating that balance.

Setsuko: At first, I used a cold tone in everything leading up to the chorus, and then ratcheted it up when I hit the chorus. But then Tsubasa Harihara, another member of Kuhaku Gokko who’s an ardent fan of Hiroyuki, said “Even if you go with a cold approach, give it the feel of wearing an oversized hoodie, with the hood pulled low so you can’t see your face, walking quickly with your eyes downturned.” That got me thinking that the song would work better if I approached it with more of a hip-hop mindset, which is why I ended up singing it with a rap battle feel.

Okamoto, what did you think upon hearing the completed “VORTEX?”

Okamoto: Like everyone says, it’s a simple and stylish song, but that also made it hard to put pictures to. As Hiroyuki mentioned, this song focuses on the cool aspects of Mechanical Arms, as epitomized by its battle scenes, so when I worked on the video, I also approached it with a rap battle feel. But Mechanical Arms also has comical elements, so I wanted to be a bit playful, too. I tried putting in some comical scenes in the opening video, and they ended up also going really well with the song. The song is simple, but I could also feel a lot of depth to it.

What about the ending theme, “karma?”

Sawano: I handle the incidental music in Mechanical Arms, too, so to tie in the incidental music with the theme song, I wanted to synchronize the main theme of the show with either the opening or ending themes. Ultimately, I decided to use the main theme melody in the ending theme, “karma.” As far as the lyrics, the opening’s mainly in English, but I wanted the ending to be in Japanese. SennaRin wrote the lyrics for “karma,” and I’ve long found her Japanese lyrics to have a unique and interesting aesthetic. She’s pretty close in age to Setsuko, too, and I thought it would be best to have someone of similar age sing it.

Setsuko: Partly because “karma” is a ballad, I was able to sing in the way I usually sing, and going into pre-production, I found it easy to put emotion into my singing. I didn’t struggle as much as I did with “VORTEX.” I was also able to sing the way I wanted when we did the main recording.

Okamoto: I found “karma” to be hard to create animation for, in its own way. I wasn’t in charge of the ending video. Other staff was responsible for that, but I have a vivid memory of the staff thinking about the meaning of the lyrics, getting totally stuck, and saying “I just can’t do it.” I told them “Don’t think so hard about it. On the surface, it’s a simple song, so why not focus on the simple parts?” I remember the whole thing really threw them for a loop.

Okamoto, as the original planner and director of Mechanical Arms, how did you interpret the lyrics to “VORTEX” and “karma”?

Okamoto: I thought trying to analyze them too deeply would be a bad choice, so I try not to think about them too hard (laughs). That said, it’s hard not to think about them. For example, both in terms of its sound and its lyrics, “VORTEX” gets the listener amped up, and then suddenly leaves you feeling empty. Hikaru, the main character in Mechanical Arms, has a lot of internal struggles, and is kind of a negatively-minded character. Alma, on the other hand, is extremely bubbly, and she supports Hikaru, but it sometimes seems there’s just nothing really to him. I think the song expresses these characters really well. It’s very impressive. With “karma,” once you start thinking about the lyrics you could just go on forever, so I’d rather leave their interpretation up to the viewers. I don’t really like when creators push their interpretations, so I chose not to think about it too much myself.

Setsuko: “VORTEX” and “karma” are opposites, but there’s a very strong feeling of connection between them. I think that connection reflects the connection between the characters of Hikaru and Alma. As Okamoto said just now, Hikaru and Alma complement each other, and it feels like “VORTEX” and “karma” do, too, while at the same time mirroring the story of Mechanical Arms.

Okamoto: The two songs convey the essence of Mechanical Arms really clearly. Like, if someone were to ask me “What kind of anime is Mechanical Arms?” I could just tell them “listen to the opening and ending themes and you’ll understand.” The simple-but-complicated, or the complicated-but-simple nature of the songs, in particular. I put a lot of thought into the creation of Mechanical Arms, but I tried to keep the ultimate finished product simple. To me, it feels like Setsuko and Hiroyuki have expressed that same thing directly, through their music.

—This interview by Hikaru Sudo first appeared on Billboard Japan