As expected, the Tokyo Metropolitan Assembly on Wednesday passed a controversial bill to further restrict the sale or rental to minors of manga and anime containing "extreme" depictions of sexual acts.

The amendment to the Youth Healthy Development Ordinance, which already prohibits the sale of "harmful publications" to anyone under the age of 18, also calls for the industry to self-regulate by toning down content designed for general release.

Requirements for self-regulation and restrictions on sales will take effect on April 1 and July 1, respectively. The amended ordinance includes a non-binding clause stating that the city government will carefully consider a work's artistic and social merits in the evaluation process. According to BBC News, publishers, studios and retailers who break the law face fines of up to 300,000 yen (about $3,575).

The bill has generated strong opposition from publishers and creators. On Friday 10 Japanese publishers, including including Kadokawa Shoten, Shueisha, Shogakukan and Kodansha, announced they will boycott next year’s Tokyo International Anime Fair, sponsored by the Tokyo government.