Attack on Titan Studio Reveals Use of Generative AI in New Anime Opening

Wit Studio, the renowned Japanese animation powerhouse known for hits like Attack on Titan, Spy x Family, and Vinland Saga, has officially acknowledged that “generative AI was utilized in the production process” of its latest project, Ascendance of a Bookworm. This revelation comes shortly after the premiere of the anime’s fourth season on April 4, which sparked fan inquiries about the background art featured in the opening sequence.

In a statement on their official website, Wit Studio explained, “Regarding our anime production, ‘Ascendance of a Bookworm: The Lord’s Adopted Daughter’ (hereinafter referred to as ‘this work’), we conducted an investigation into the production process of this work, including the opening sequence, based on the feedback we received after April 4, 2026. As a result, we confirmed that [genAI] was used in the production process of some cuts in the opening sequence.”

The use of AI-generated backgrounds in the opening has drawn criticism, leading to the removal of the opening song from Crunchyroll’s YouTube channel. Wit Studio has stated that “the opening sequence will be replaced with the completed version using the aforementioned background art materials” for all upcoming episodes of Ascendance of a Bookworm.

This anime adapts a light novel series that began in 2013, telling the story of a librarian who is crushed by books and reincarnated as a child in a world where literature is a luxury for the elite. The anime first aired in 2019, with Wit Studio taking over production for the fourth season that just launched.

The studio emphasized that while they are keen on exploring new technologies in video production, they have generally not allowed the use of generative AI in their projects, including this one. They acknowledged that the current situation arose from flaws in their production management and inspection systems, taking full responsibility for the oversight. They expressed sincere apologies to fans, the original author, and all involved parties.

Wit Studio clarified that NAM HAI ART, the studio responsible for the background art of Ascendance of a Bookworm, should not be held accountable for this issue. This statement aligns with comments made by director and animator Terumi Nishii, who noted earlier this year that many animation studios are already “using AI to generate rough drafts for direction corrections,” complicating the process of identifying when scenes are outsourced to other companies.