"Each country has it's own peculiar hangups around sex. Japan produces some of most extreme and bizarre erotica on the planet and yet they prohibit the explicit display of genitals." That Law is a hold over from the early days of the post war occupation. Though Japan historically has been very free minded about the depiction of sex in art, (You should see some of those old ink paintings!) During the Imperialist years, this wasn't the case. Even Kissing was banned in movies. The allied occupation actually brought back most of these freedoms, but set a definate limit when it came to showing detailed adult genitalia, or groins touching etc... I think it was this restriction that led to so many weird fetishes popping up in Japan. I mean you can't show a Penis, but you can show a tentacle. This probably also didn't hurt the rise of Lolicon in the earliest 80s adult anime OVAs. (Cream Lemon, and the Lolita series)