A staggering number of young people in Japan are not interested in sex.
Combine an economic downturn with the increasing excellence of porn and video games, then throw in female economic independence and this is the result. For all that they are decried as soshoku danshi, the position of the "herbivores" is a perfectly reasonable one.
It's likely that the modern Japanese teenage girl is ultra-materialistic. Japan has lost 'two' decades to poor economic growth. Therefore, a majority of guys in her age group are utterly unappealing.