The best they can ever hope to do is attempt to force Japanese hentai artists on twitter to deactivate by appealing to emotion in order to abuse the report system. Emotion is all they have because their laws (mostly the draconian UK and EU laws) have no effect on the people within Japan. Japan values creative freedom to the point where their perspective on it boils down to "You can draw whatever you want as long as you aren't breaking the law."
As long as the character isn't a real, identifiable person, anything depicted upon said character is fair game to the artists regardless of your moral stance. This is also the reason
shadman deserves the shit he gets because he made the autistic decision to draw porn of real, identifiable children at the time (LtCorbis, Keemstar's daughter, and Dafne Keen). Even Japanese hentai artists know better than to do that shit.