About hentai/porn
Wondering why hentai is almost all child porn, I went investigating. Wikipedia offered some interesting facts about Japanese censorship law which:
"forbids the publication of obscene materials. Specifically, depictions of male-female sexual intercourse and pubic hair are considered obscene, but bare genitalia is not."
So... were they like "I know who doesn't have pubic hair: prepubescent children; let's depict them having sex with tentacle monsters! That's much less obscene."?