The anticipated Spring 2026 anime season marked the return of one of the most beloved isekai of all time, Season 4 of Ascendance of a Bookworm. Ajia-do studio produced the first three seasons, but the latest season was picked up by WIT Studio, one of the most renowned animation studios in the country. The studio is known for many beloved shows, especially the first three seasons of Attack on Titan. Over the years, it has released several visually striking series such as Moonrise, Love Through a Prism, Vivy: Fluorite Eye’s Song, and more. Unfortunately, fans alleged the use of generative AI in the opening theme of Ascendance of a Bookworm Season 4, which left them disappointed. The anime’s latest season debuted on April 4th, 2026, and less than a week after the episode was out, the studio broke its silence on the allegations.
After confirming that generative AI was used to create certain cuts in the background art, the studio replaced the opening theme with an updated version after incorporating the redrawn background art assets. The studio also made it clear that they do not authorize the use of generative AI in any of their works. They took full responsibility for the situation, but the disappointment has yet to disappear. Amid the controversy, the studio also released Agents of the Four Seasons anime this Spring 2026. While the anime was released before Ascendance of a Bookworm Season 4, WIT Studio returned with a new music video for Orangestar, who performed the opening theme.
WIT Studio Creates a Brand New Animation For The Opening Theme’s Artist
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Orangestar performed the opening theme titled Petals for the new anime and later released a full-length video of the song. Usually, the theme songs in the anime run for 90 seconds, and the full-length version is released later on. WIT Studio provided the animation for the music video, and it’s just as gorgeous as ever. The song is also available on Spotify, Apple Music, YouTube Music, and many other platforms.
What Is Agents of the Four Seasons About?
Image Courtesy of Wit Studio
The anime is based on a light novel written by Kana Akatsuki, the same creator of Kyoto Animation’s acclaimed Violet Evergarden series. The story is set in a world where winter was once the only season. However, since it was a lonely existence, Spring was created to love. Over time, the planet wished for more, and thus, Summer and Autumn were born. Those who carry the cycle are known as Agents of the Four Seasons.
Unfortunately, Hinagiku, the Agent of Spring, disappeared 10 years ago, taking the beautiful season of spring with her. She returns after facing unbelievable hardship so she can restore the cycle to its former glory, as the myth about her love towards Winter is passed down. The light novel was released in 2021 and has already reached its conclusion. The anime is listed for 14 episodes and streams new episodes on Crunchyroll every Saturday at 9:30 A.M. PT.
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