Banning Fictional Rape
http://www.yestofreedom.org/arguments/
http://www.yestofreedom.org/2009/08/01/a-timeline-of-events/
It's fairly long but the timeline at the bottom is more concise.
In short CEDAW (Convention on the Elimination of Discrimination Against Women) considers Japan's protection of fictional women from fictional rape to be one of the most serious problems in the world today and is trying to institute UN sanctions against Japan as a result.
Of course with the Internet being an international rape highway I don't see what they think they're even capable of accomplishing if Japan caves.