Is there some philosophical/ethics work done on the question which fictional crimes, taboo breaks or unethical behavior are okay and which aren't? Iirc Japan ta

Is there some philosophical/ethics work done on the question which fictional crimes, taboo breaks or unethical behavior are okay and which aren't? Iirc Japan takes the extreme position of legalizing all fictional wrongdoings, whereas the west is okay with fictional violence (e.g. murder mysteries), but not okay with some other things. Where to draw the line?