The Academy Awards (Oscars) recently released a special feature on their official YouTube channel titled “Inside The Animation & Artwork of ‘Demon Slayer: Kimetsu no Yaiba Infinity Castle’.”
With the 2025 release of Demon Slayer: Kimetsu no Yaiba Infinity Castle Arc: Part 1 – Akaza’s Return, the spotlight has turned to the studio behind the phenomenon. As the global animation industry increasingly shifts toward efficient 3DCG pipelines, why does ufotable persist in drawing by hand? The video reveals the studio’s aesthetic philosophy born from “overwhelming inefficiency” and documents the intense struggle on the production floor.
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“Overwhelming Inefficiency”: A Choice Against the Global Tide
In the opening of the footage, narrator Takahiro Sakurai describes ufotable’s stance with the phrase “overwhelming inefficiency.” While 3DCG technology evolves and becomes the mainstream standard for animation production worldwide, the studio has chosen the path of drawing character movements from scratch.
Hikaru Kondo, the representative of ufotable and the project’s Chief Director, explains the reasoning behind this decision: “There are things only that specific artist can draw. There are pictures that can only be drawn in that specific moment.” He asserts that the “instability” unique to hand-drawn art is precisely its charm, capable of moving the hearts of the audience. The video suggests that when this human, analog power fuses with the digital technology ufotable has cultivated over many years, the true value of Demon Slayer is realized.
The Strength of In-House Production Supporting a 2,200-Cut Struggle
For the Infinity Castle Arc, while advanced 3DCG technology is utilized, the number of animation staff wielding brushes exceeds the 3D staff by more than five times. The team tackled a staggering 2,200 cuts.
What is particularly noteworthy is the production structure. Chief Director Kondo builds the framework, while Director Haruo Sotozaki and Chief Animation Director Akira Matsushima inspect every single key frame. Because “the same scene becomes a completely different picture depending on who draws it,” allocating the right cut to the right artist is considered extremely critical.
ufotable is comprised of members who have been creating works together for five, ten, or even twenty years. These “artisans,” who know each other’s strengths inside and out, layer their lines with total dedication. The video explains that this extremely high rate of in-house production creates a high-intensity environment where the lines drawn by one person ignite the soul of another.
“Ten Years to Render”: Constructing the Anomaly of the Infinity Castle
The setting of the story, the “Infinity Castle,” is a complex and bizarre architectural space that ignores gravity and perspective. Yuichi Terao, the Digital Chief, reveals that when constructing these visuals, the initial rendering calculation produced a hopeless figure: “It would take 10 years to complete.”
However, the team did not give up. They achieved a fusion of lighting and compositing by the digital imaging department with the soulful line art from the animation department. As Terao, serving as the Finishing Director, puts it, they wanted to “wrap the heat of the hand-drawn art in digital.” By adding 3D camera work and effects to 2D animation, they created an overwhelming sense of depth and density on the screen.
Verifying emotional expression in the lines down to a single pixel, and remixing the music countless times, the workload is described as a level where “no matter how much you draw, it never ends.”
Beyond the “Battlefield” of Animation
toward the end of the video, the narrator describes the production site using the words of the antagonist Muzan Kibutsuji: “hell” or a “battlefield.” Yet, as a result of continuing to challenge this arduous battle, the film reached completion.
“Visuals that are realistic but not reality itself; painting emotions with lines and light.” That is the true identity of Demon Slayer: Kimetsu no Yaiba Infinity Castle. The fact that the official Academy Awards channel produced this feature serves as proof that this work is transcending the framework of “Japanese anime” and is being evaluated as a piece of global visual art.