Welcome to Demon School! Iruma-kun Season 4 welcomes two highly anticipated stories: the “Music Festival Arc” and the “Dem-Dol Games Arc.” Faced with the requirement to participate in the Music Festival to rank up as demons, the Misfit Class finds out they have another classmate, Purson Soi, a voiceless character who’s been in the background for the last three seasons. Setsuo Ito, best known for voicing Mob in Mob Psycho 100, has brought Purson Soi to life with his fast-paced dialogue. While Ito is one of the newest additions to the cast, chief director Makoto Moriwaki has been directing the series since the first season. At Anime NYC 2026, Anime Trending had the chance to chat with the two about their musical backgrounds, the directorial vision driving the new season, and how Ito landed the role as Purson.
This interview was conducted via an interpreter and has been edited for clarity.
Purson Soi was a background presence for three seasons before we finally heard his voice this season. What was the audition process like, and how did you land the role?
Setsuo Ito: For the audition, the part I had to read was one of Purson’s very long and very fast lines. I could barely breathe trying to do it, and by the time I finished, my mind went blank, and I thought, “Wait, I have to really do something like this for this role?” As for why I actually got the role, I’m not totally sure. I just heard from someone else that it was partly because I sort of look like Purson. I also heard that Nishi-sensei wanted me for the role because they’d seen me in another series and enjoyed my performance. Honestly, I was terrible at tongue twisters or fast talking like he does, so I really thought I’d failed the audition.
This season, Purson Soi becomes a key player in the “Music Festival Arc,” putting you alongside cast members like Ayumu Murase and Ryohei Kimura, who’ve been part of the series since Season 1. What was it like to record with them? Were you given any pieces of advice or interesting stories from the recording booth?
Setsuo Ito: For me, obviously, they’re both my senpai in this industry, and I’d seen them in other work before, but I’d really only seen them in passing. I didn’t get to talk to them much. So I was honestly very nervous, but the mood at all the recording sessions has been very warm and welcoming, from them and the other cast members too. Even though I’d just joined the cast, they’ve all been very welcoming.
It’s not really advice, but we started going to dinner more, and we’d have conversations. One of the things we’d talk about is the fact that Purson Soi doesn’t really talk for three seasons. The cast was very curious about what he’d sound like finally. When Murase-san found out what he sounds like, he laughed, but it was more of a compliment. He said he thought it really fit, so I was very honored and took it as a positive thing. Also, from going to dinner together, Kimura-san always acts like the big brother to all of us.
Purson Soi is a quiet person until he opens his mouth and starts talking, which makes it funnier when he actually speaks. How did you approach building his character?
Setsuo Ito: One of the things I really concentrated on is the gap. He goes from zero to speaking insanely fast. I did want that difference to be a little snappy, but I also didn’t want him to come off as someone who’s not very nice, so I tried to balance that.
Moriwaki-san, you’ve directed Welcome to Demon School! Iruma-kun across four seasons, and this time you’ve stepped up to be the chief director. Has that transition changed anything for you, and how has it shaped your approach this season?
Makoto Moriwaki: The director is responsible for everything. The chief director is more like the shadow behind the director — they watch over the director and point things out. They’ll say, “Maybe this part isn’t exactly how it should be,” or what things should be changed. As for workload, time-wise, it’s gotten easier for me — but that’s just the time aspect. I still have a lot more responsibility in this role.
The “Thirteen Crowns Arc” was adapted ahead of the “Dem-dol Games Arc,” reversing their order from the manga. Could you share what led to that decision and your thoughts on the execution?
Makoto Moriwaki: For seasons 1 through 3, the climax of the story was usually at the end. It’s sort of like cooking and courses, where you want to make the best menu for people to watch. Changing that order seemed like the best thing to do. In this season, the climax didn’t happen at the end — it happened in Episode 7 already. I didn’t want to be done by Episode 7, and I wanted people to keep watching, so that’s the “main dish” I saved for the end.
Purson Soi is a skilled trumpet player. Have you played an instrument yourself, or is there one you’d like to learn?
Setsuo Ito: Actually, I played the guitar, electric guitar, bass, and drums. I was also in a brass band as a kid, playing percussion, so I played drums. In my high school band, I played guitar, but then my senpai said we needed a bass player, so I ended up playing bass.
I’ve played various instruments throughout my life. When I was in brass band, I did have a trumpet in my hands at one point and tried to play it, but no sound came out. Basically, I couldn’t hit the high note, the high C. Now, if there’s an instrument I want to learn, it’s actually the trumpet.
Makoto Moriwaki: In elementary school, I played the recorder. Then in middle school, my big brother played guitar, so I learned guitar too, and I can play most of the chords. But I decided much later that I wanted to learn how to play the piano. I can definitely relate to Soi on this — you can’t just go screaming and yelling, letting your anger or feelings out like that, so it’d be great to just bang all those feelings out on the piano instead. Also, I smoke, so I think instead of relieving stress that way, I could bang on the piano and release my stress instead. In the end, that would be much better for my health [laughs].
Looking ahead to the “Dem-dol Games Arc,” what are you most excited for fans to see?
Setsuo Ito: Personally, my character’s arc is pretty much finished for now, at least through the first half of Season 4, so I’m not really involved much in that part. But I get to see how hard the cast and staff, led by chief director Moriwaki-san, are working on it, so I know it’s going to look absolutely amazing. As a reader and a viewer myself, I’m very excited to see how it turns out, so I hope everyone looks forward to it.
Makoto Moriwaki: One of the things coming up is a character named Gyari, and how in love she is. I can’t give too many details right now because it might be a spoiler, but Gyari is very passionate. She’s basically like a storm. I want people to pay attention to that part. The season also ends very well, so I hope everyone will watch to the end and enjoy it.
Welcome to Demon School! Iruma-kun Season 4 is currently streaming on Crunchyroll.
Questions by Gerrymelyn Casupang. Interview conducted by Isabelle Lee.
