The age of consent isn't really 13: It's 16 or 18 depending on the prefecture, but if it's a true love relationship (or something like that I can't the name now), usually considered that when the parents of both parts of the relationship are ok with it, then it is permitted, though the police can intervene if they see something fishy.
The age of consent isn't really 13: It's 16 or 18 depending on the prefecture, but if it's a true love relationship (or something like that I can't the name now), usually considered that when the parents of both parts of the relationship are ok with it, then it is permitted, though the police can intervene if they see something fishy.