Shueisha, the publisher of Weekly Shonen Jump - the magazine known for popular series like One Piece and Dragon Ball - is among the companies issuing the legal warning to OpenAI. Screenshot (left): One Piece/ Toei Animation

Several Japanese anime and manga publishing companies have jointly threatened legal action against OpenAI, alleging copyright infringement by its Sora 2 video generation app.

According to a report by the Japanese daily The Asahi Shimbun, the companies - including major manga publishers Shueisha, Kadokawa, Kodansha, and Shogakukan - claim the AI service creates videos using their anime characters without permission.

In a translated version of the official statement, the group said AI advances "should not be achieved by trampling on the dignity of artists who pour their heart and soul into their works". The statement specifically criticised OpenAI's "opt-out" approach, where copyright holders must request removal of their content, arguing that this fails to protect rights holders adequately.

The report by Asahi Shimbun states that the publishers, 17 in total, were joined by industry organisations including the Japan Cartoonists Association and the Association of Japanese Animations. They demanded that OpenAI obtain approval for using copyrighted material during both the AI training and video generation processes. The group warned they would take "appropriate and strict action" from both legal and ethical perspectives to protect creative works.

The action follows a late October request from Japan's Content Overseas Distribution Association, which includes Shueisha and Toei Animation, asking OpenAI to stop its AI from learning from member companies' content without prior approval, further states the report.