Based on a Japanese light novel series written by Kôsuke Unagi and illustrated by Super Zombie. Unagi began writing the fantasy adventure story on the Shousetsuka ni Narou website in October 2020. Kodansha began publishing the series with illustration by Super Zombie under its Ranobe Books imprint in June 2021. The third volume was released in July 2022.
The original light novel spawned a manga adaptation by Yuuri that began serialization on Kodansha's Magazine pocket website in June 2021. Kodansha shipped the seventh volume on April 9 and will release the eighth volume on September 9, 2024.
In Episode 13 "Biblion, the Book Spirit" when they first open the book, you can see the four elemental sigils from Avatar: The Last Airbender.