Demon Slayer: Kimetsu no Yaiba is a Japanese fantasy franchise that has dominated the world since 2016. The anime series, released in 2019, propelled the franchise to new heights. The first feature-length anime film in the series, Demon Slayer: Kimetsu no Yaiba – The Movie: Mugen Train, slaughtered box office records in the early 2020s to become the highest-grossing anime film of all time.

Demon Slayer: Kimetsu no Yaiba – The Movie: Infinity Castle intends to do the same, but on a much larger scale. This film represents the beginning of the end for the anime adaption, serving as part one of a trilogy based on the final story arc, Infinity Castle. The plot follows Tanjiro, Giyu, Shinobu, and the rest of the Demon Slayers Corps after being ensnared in a deadly trap. They must fight for their lives against Muzan, Doma, Akaza and the other high-ranking demons in the dimensional-expanding stronghold known as “The Infinity Castle”.

In anticipation of the biggest anime film release of 2025, we sat down with the stars from the English voice cast, Zach Aguilar (Tanjiro Kamado) and Supa-Star alumna Johnny Yong Bosch (Giyu Tomioka), to discuss their journey with Demon Slayer.

They have been part of the series since the very beginning; did they expect Demon Slayer to become a pop culture phenomenon?

“No,” Johnny laughed. “Same, not like this, we’re about to attend a premiere at the Grauman’s Chinese Theatre in Hollywood, that’s insane to me!” Zach exclaimed. “People in my family who don’t even know about anime are like, ‘Oh, yeah, we started watching Demon Slayer, we’re going to see the movie.’ And I’m like, ‘What, my cousins don’t know what anime is, do they?’ Now, they’re like, ‘You do voices for anime?!’ And I’m like, ‘Yeah, I do,’” he smiled.

Did they know where the story was heading before their recording sessions? “I cheated and read ahead a while ago,” said Johnny. “Yeah, me too,” Zach confirmed. “I read the manga as it was released. I loved where the story went.”

Were they prepared for the scale of Infinity Castle? “I was prepared, but I felt nervous, even though our recording process was the same as before,” Zach explained. “I felt the pressure because I knew how big the scale of this movie was going to be, especially after Mugen Train. I have always brought my A-game to recording sessions, but this time, it’s like my A-plus-plus-game.”

“Zach’s right, you feel the weight of it more, which I prefer not to,” Johnny laughed. “I didn’t want to think about that. I needed to focus on getting lost in character. But I couldn’t help but feel like, ‘Oh boy, [the scale of Demon Slayer] has gotten pretty big.’”

“This speaks more about my nerves when going into the recording sessions,” said Zach. “I would wake up early beforehand and do thirty minutes of vocal warmups, going up and down on a five-tone scale.” He brought his hand to his mouth and performed a short demonstration of his vocal warmup. “What has been a saving grace for my voice is my vocal mister, which is a nebuliser for your voice; it’s been freaking awesome! I used the mister, cleared out my sinuses, and I had this whole routine. I really made sure I had every box ticked before walking into the recording booth.”

“I didn’t have anything,” Johnny added. ”I chatted to the director about where the character was coming from and what’s going on. I cleared my throat, I heard the Japanese reference, and I just jumped in. It would be different if I was playing Zach’s part. Tanjiro does a lot more shouting, and his pitch is higher. For me, I can wake up in Giyu’s voice. He’s not very emotional, at least he doesn’t show it,” Johnny concluded. “Mr. Giyu!” Zach exclaimed in his Tanjiro voice. They both burst into laughter.

Like many other families, superstar Channing Tatum watches Demon Slayer religiously with his daughter. Tatum joined the voice cast for Infinity Castle as Keizo, a key figure in Akaza’s past. Have Zach and Johnny crossed paths with Tatum while working on this film?

“He was getting water for us while we were working,” Johnny joked. “No, we did not, but we will hopefully see him at the premiere.” Zach smiled, “so many people watch this show with their kids, it’s really cool that he’s a part of the film. I’m a huge fan, I hope I have a chance to meet him at the premiere.”

“I think it’s awesome that he and his daughter are fans; it validates things in a way. Hollywood can’t ignore the level that Demon Slayer has reached,” Johnny declared.

What are their hopes for fans when they watch Infinity Castle on the big screen? “I really hope they enjoy it so much they will see it again, and again. Obviously, it was a lot of fun to work on, and we’re all very proud of our work. I’m excited to see it with an audience, even though it’s a bit scary, but it’d be neat.” Johnny nodded.

“Yeah, I’m excited to watch it with the audience”, Zach grinned. “When I was working on Infinity Castle, I was counting the moments; at this moment, audiences will go ‘Oh!’ or at this moment they will all start cheering.  I hope people love it, I hope they go see it and experience the vastness that is the Infinity Castle. I hope they are prepared for the emotional roller coaster that is Demon Slayer.”

‘Demon Slayer: Kimetsu no Yaiba Infinity Castle‘ is in cinemas September 11