[Nyororin]

I don`t think you see it as strongly, but there is a definite difference in the play styles and interests of boys and girls after a certain point so they end up heading off into their own groups.

Rather than the other sex being "yucky", it seems there is more a feeling of "why would you want to play with them?" because the interests just don`t overlap. I have yet to see any sort of directed exclusion, and there is value placed on relationships between the sexes so you don`t see outright shunning of the other.

But in the end, boys play differently than girls, so the groups head off in their own directions.