kill-chan The thing with the her face... yeah. But for example Nana Asakawa is explicitly and literally marketed as someone with a "children's face and big breasts of one in a thousand years" (sennen ni ichido no dôgan kyonyû).
I think what some people don't understand about Japan is the thing of dividing reality and fiction. The latter can be much more free. You have the wildest anime and entertainment in Japan but a rather serious everyday life.
In the West people have been molded into thinking "yuck, she's below legal age!", where a century ago or so, the perceived legal age was lower. I do not endorse the actual mistreatment of children in any way, but there is purely aesthetic reason (in contradiction with the reality of tough everyday life) for dumping old women in favor of young ones.