Classic anime outside of Hayao Miyazaki’s work has never really made serious inroads with the Academy voters during Oscar season, but Crunchyroll is looking to change that with “Demon Slayer: Infinity Castle.” The feature shattered box office records, becoming the highest-grossing Japanese film of all time, earning $682 million worldwide. It also landed a Golden Globe nomination for motion picture — animated.

“Demon Slayer: Infinity Castle” follows Tanjiro Kamado and the Demon Slayer Corps in a battle against Muzan Kibutsuji and the Upper Moons inside his hideout, known as the Infinity Castle.

The animated feature, produced by Ufotable, blends both 2D and CG styles.

Director Haruo Sotozaki explains that the characters were animated by hand, and one of the main challenges was “marrying the 2D frames within the CG background and environments.” Speaking via a translator, he adds, “It was one of the hardest marriages we’ve had to take on.”

Matching the 2D animation to 3D back grounds required an additional step in the production pipeline.
“We would send the key frames to the 3D team,” Sotozaki says. “They would try to match those key frame animations to the surrounding 3D environments.”

Once the match was achieved, the frames were sent back to the animators to polish each one.

As far as the story is concerned, Ufotable president and chief director Hikaru Kondo reveals that the film was originally over three hours long after storyboarding. However, even at that length, there was no clear “overall groove of what the journey was.”

For the animators and the studio, it was crucial to ensure emotional investment for the audience, given how beloved the franchise, story and characters are.

The key was not to rush the process — the film took over three and a half years to make. “We’ve been building up to this moment from the ‘Unwavering Resolve’ arc, laying it down for the fandom and the
audience to really buy into what is happening in the ‘Infinity Castle,’” Kondo says.

It was a massive undertaking, but the team had a blueprint.

They had faced a similar challenge when creating “Demon Slayer: Kimetsu no Yaiba — The Movie: Mugen Train.” “There were a lot of questions about how you can take all of this information and put it into a single film. I think that learning has been applied to ‘Infinity Castle,’” Kondo says.

Cinematographer Yuichi Terao played a key role in balancing the visual spectacle of action sequences and battles with an engaging story.

Once the emotional backbone was established, it was also about creating an “epic space.” Everything had to take place within the Infinity Castle itself. The Infinity Castle first appeared in the “Unwavering Resolve” arc of the TV series, but now the studio had to create something even bigger.

Amid the action and drama, there’s also destruction, which Terao says gives fans something new to experience. “We were getting all of the destructive effects and the physics to work this hybrid effect that we’ve designed. As a member of the audience, it’s a fun experience, but we all collectively as the studio had to work together to put it onto the screen,” he says.

Crunchyroll remains hopeful that “Demon Slayer” will connect with Oscar voters and bring greater anime representation to the Academy Awards. Mitchel Berger, Crunchyroll exec VP of global commerce. has been on the FYC trail. He notes that being part of the awards conversation is a way to elevate the art form. “It’s a beautiful piece of artwork,” he says of ‘Demon Slayer.” “The craftsmanship, the care, and the love that goes into this — just being able to expose people to that is a wonderful thing.”