The animation industry has expressed concern over the Tokyo International Anime Fair 2011 because a group of publishers plans to boycott the event as a protest over stricter regulations on sexually explicit manga and "anime."

The threatened pullout by 10 major comic book publishers, including Kodansha Ltd., Shogakukan Inc. and Shueisha Inc., threatens to jeopardize the fair, the Association of Japanese Animation, which serves as the event's secretariat, said in a statement.

The association has also expressed regret over the amendment of a Tokyo Metropolitan Government ordinance that toughens regulations on the sale of manga and anime containing "extreme" depictions of sexual acts.