Inoue Shin-ichiro, the president of Kadokawa Shoten, announced in his twitter that Kadokawa will boycott Tokyo International Anime Fair 2011(TAF2010) to protest against the anime & manga regulation bill submitted by Tokyo Metropolitan Government. The chairperson of TAF executive committee is the governor of Tokyo, who strongly supports the bill and have called mangaka "lowly people".

The revised regulation bill proposes to prohibit the publishers to sell minors (under 18) anime and manga which:
1. provoke sexual sensation or induce crimes.
2. positively describe illegal sexual acts or incest.

Numbers of groups have opposed to the regulation bill because:
1. the administration can make arbitrary interpretations by the ambiguous expressions of the bill.
2. there is no scientific evidence that proves sexual expressions in anime and manga could disturb the building of children's judgement on sex.
3. the distribution of manga and anime will be severely restricted once designated as adult materials (e.g. selling at convenience stores and airing on TV will be prohibited)

List of groups opposing to the new bill
Japan Cartoonists Association
Manga Japan
Comic Authors in the 21st Century
Japan P.E.N. Club
Japan Playwrights Association
Japan Civil Liberties Union
Tokyo Lawyers Association
Publication Ethics Committee
Publication Distribution Control Committee
Japan Federation of Publishing Workers' Unions
Japan Writers Guild
Japan Federation of Bar Association
Japan Society for Studies in Cartoon and Comics

Source: Inoue's tweet, Wikipedia