*edited*
Japan has long had a more mature view on sex; it is seen as something natural for everyone to do; the only taboo has come from the American occupation; and how they have conformed to western society and views in recent (recent being the last 200 years or so) years.
I don't know how Japan does it's sex education, but Hentai is NOT a part of it; Hentai, Ecchi and the likes are really adult only material; and a small demographic at that.
gah; MMM you got here fisrt