‘Infinity Castle’ Voice Actors Reflect on the Beginning of the End of ‘Demon Slayer’

Demon Slayer: Infinity Castle, the first of a film trilogy marking the end of the mega-popular anime, hits theaters this month. It follows Tanjiro Kamado, a young man who enlists in the Demon Slayer Corps. He does so for the sake of learning how to help his little sister Nezuko after their family’s massacre leaves her transformed into a demon.

Infinity Castle serves as the follow-up to the anime’s fourth season, wherein Tanjiro and his fellow Demon Slayer Corps members, including his kinda-sorta mentor Giyu, are teleported straight into the heart of the final big bad Demon’s lair.

io9 spoke with Tanjiro voice actor Zach Aguilar and Giyu voice actor Johnny Yong Bosch about taking part in a seminal moment in anime history with one of the industry’s most successful shows—both on streaming and in terms of popularizing the trend of anime theatrical releases—nearing its finish.

Isaiah Colbert, io9: Infinity Castle isn’t just another anime film—it’s poised to break box office records and redefine what theatrical anime releases can achieve. What does it mean to you, as voice actors, to be part of a project that’s reshaping how both studios and audiences are treating anime films?

Zach Aguilar: It’s mind-blowing; it’s about time, guys! I’ve known anime was awesome since I was in elementary school. Since I was a little kid, I started watching anime, and I was picked on for it. But not anymore! Now… Biff is in my DMs saying how cool I am, trying to get an invite to this premiere, you know what I’m saying? I’m like… Biff who?

I’m just kidding! But to be honest, it’s been absolutely crazy. It’s insane to see anime on this level, on this scale. I know the reception for the film has been absolutely mind-blowing. I’m just stoked to be a part of it, and I can’t wait to see it continue to blow people’s minds too.

io9: And you as well, Johnny?

Johnny Yong Bosch: Oh yes. I was hoping you were just gonna go on to another question.

io9: No, no, no, no. 

Bosch: Yeah, well, I mean, I think it’s awesome. It’s all thanks to the fans and to Demon Slayerbeing a great story and having great characters, and the animation is awesome. I just said this in the previous [interview] . I think it’s really kind of earned its place, but it’s nice. I agree with Zach. There was definitely a time when [anime] wasn’t accepted. It was unacceptable to watch anime and looked down upon. Even going to conventions occasionally, you’d get the dark corner. But thanks to the fans and to this great story and animation, here we are.

io9: Tanjiro and Giyu are both emotionally layered characters, and this film trilogy arc looks to push them to their limits. What came naturally to you in revisiting these roles, and what challenged you this time around?

Aguilar: That’s a good question. Going into this film, I mean, every time, I’ve always wanted to give Demon Slayer 110 percent. I’ve always wanted to give my best as Tanjiro. He’s the emotional heart of the story. I will say, for me, going into this movie, wanting to give 110 percent and leave nothing on the table, there were certain lines I kept doing to the point where I lost my voice because I kept wanting to do a specific line (that I can’t say). But I kept wanting to do a specific line. I’m like, “No, I can do it stronger. There’s something else I can add in here. When you hear that line and you know it’s really good, but you’re like… there’s a little bit of spice; there’s something extra you can add in there to really drive it home.

I will say, we did get that take. It was 100 percent worth it. I went on vocal rest for a day, but I gave my all to this film, to Tanjiro, every single emotion, everything. I promise you will go to the theater, you will hear it, you will feel it.

io9: And you as well, Johnny?

Bosch: I’ve been kind of waiting for this moment, you know? Giyu’s got this deep sense of honor, and he’s haunted by his past. He’s got this guilt, but he does feel connected to Tanjiro, and so there’s something very traditional samurai about him that I really like. We got to see glimpses of it, but I’m trying to make sure that I don’t spoil anything saying this, but yeah. I’ve kinda wanted to see him get to the point where he shows that he’s willing to risk everything, even his own life. We get to see him get to this really awesome moment in this film. And again, it’s just something I’ve been waiting for for a long time.

Channing and Everly Tatum at the NY premiere of Demon Slayer: Kimetsu no Yaiba -To the Hashira Training- World Tour!! 🔥 pic.twitter.com/DjcJw4ibIA

— Crunchyroll (@Crunchyroll) February 11, 2024

io9: Demon Slayer: Infinity Castle made headlines with Channing Tatum joining the cast as Keizo in a wild crossover moment. How did it feel to find out that a Hollywood star was a big fan and got to be a part of the Demon Slayer universe? Did it encapsulate the anime’s global reach, or was it just getting into the booth, business as usual, for you guys?

Aguilar: I think it’s freaking awesome. I had heard that Channing Tatum and his daughter were big fans of the series, so I think it’s cool that he gets to be a part of it as well. I can’t wait to go around and tell everybody, “You know, my close personal friend, Channing Tatum, is in the movie. It’s not a big deal or anything, but it kinda is.”

He is such an accomplished actor. I’m a huge fan of his work. I actually haven’t had a chance to meet him yet, so I’m hoping that comes up either with this premiere or maybe some other press event or something we get to do in the future. It’s super cool, and I’m excited to hear his performance in the film. I’m sure he killed it.

Bosch: I think it’s cool. He might be the first one, but we’ll probably see more celebrities admitting they like the anime.

io9: Infinity Castle is the beginning of the end for the final arc of an anime that, for a lot of fans, has been their formative years. Coming into it, there’s been a lot of debate on what’ll be the next show for people to jump into to lead into the next generation, as a lot of shows are coming toward their final curtain calls. What does it mean to be a part of that chapter in anime history, and what shows would you recommend to fans to check out as they’re waiting for this film and its sequel? 

Bosch: So you want us to plug other shows?

io9:We can keep it in the Demon Slayer house. whatever you feel like.

Aguilar: I’m like, “Plug some other shows? Hold on a sec, let me take a look at my IMDb real quick.” My personal favorite, funnily enough, it’s an anime called Your Lie in April. I’m a pianist; I have played my entire life. So, that show has a special place in my heart.

There’s a lot of great shonen shows out there. I hear all the time about the next upcoming “What’s the next big anime?” and “The next craziest thing.” I used to be way better about keeping up with it, but I haven’t lately. [My] schedule’s been a little packed and crazy. But there’s a lot of great shows out there. I don’t know if there’s anything Johnny wants to plug?

Bosch: Just go watch all the anime.

Before you start the herculean task of watching all the anime, you can look forward to watching Demon Slayer: Infinity Castle when it hits theaters September 12.

Want more io9 news? Check out when to expect the latest Marvel, Star Wars, and Star Trek releases, what’s next for the DC Universe on film and TV, and everything you need to know about the future of Doctor Who.