So in 46 ou 47 prefectures you can't have sex with a 13 to 17 years old girl/boy if you're older ? Excuse me, I don't know for the law, but do you really think that law is enforced ? You see tens and tens of relationships involving teachers and student in manga, and students are typically between 13 and 18: do you think there would be that much representations of this kind of relationships, if there weren't enough real cases ? Hey, not talking about hentai, which I hate by the way. I'm talking about your usual romance manga.
My bet is, that law isn't enforced in most cases, or is only when violence is concerned. Probably under 13 too, but that is another story ...
Law can't be applied uniformly in matter of human reationships. Those who don't think so, please get out your *** of your republican/French Revolutionary/universalist point of view. For millenia, justice was done on a personal, or ethnic basis, and that system has its cons and its pros. Its pros being it takes in account the cultural background of people, the way they are meant to behave, to judge them. Fairly logical, to my own opinion.
I would like to add something else: why, when talking about sexuality, everyone think (it's obvious) about pregnancy and stuff? Not everything in sex is coït, sexual intercourse etc. You actually don't have to be gay or lesbian to like better the rest. And the rest is ... without consequences, except for sexually transmissible illnesses, which are anyway easily avoidable, as long as you have a tiny "technical" knowledge, and if what you want is definitely not to reproduce ... which is the motivation of MOST sexual acts, if not, we wouldn't bother that much with contraceptives right ?
Sorry for the "technical" part, but when it can hugely shape one's opinion on a national habit/social practice, we can't help but clarify things bluntly. Shall I add that it is well-known that in the past, relationships between senpai and kohai were common, and even a great educative incentive ? And that girls and boys are culturaly separated ? It means the "senpai" you're interacting with, for all odds, is a same-sex person. So yeah, homosexuality, or better, pederasty, as anthropologicaly that's the term, was common in pre-defeat Japan. That obviously explain why they are so "leniant" with these questions of sexuality and age of consent. They just don't see the problem, and I doubt old people who use to live things now officialy prohibited, consider they have been "raped", "violented", "traumatized" ... They will talk you about "beauty", "love", "respect", "magic" etc, if they ever talk to you, because they are likely to feel our fundamental inability as repressed/so-called-sexually-liberated/feminist Westerner, to compute what they could tell us. Stop judging people on behalf of your narrow-mindedness ... especially in matter of sex, for heaven's sake !
I ain't saying to break the law, so there's no way "legality" ( or even less "morality") shall interfere with free thinking.
For like-minded people, especially Asian, you can mail me, I'm looking for getting to know you.