It's such an interesting question! I've been working out a Prince of Tennis 'all the tennis players always were women' au, and the way it falls out is intriguing. I mean, Momoshiro winds up trying really, really hard (and mostly failing) to be a hyper feminine girly girl (mostly failing because she is loud and definitely an alpha personality, and also actually takes tennis extremely seriously, and about all she's got right is the 'boys are pretty' and 'frilly short skirts!'), while Echizen is still determinedly considering herself a "kid" and ignoring the whole issue - which she can get away with, mostly, because she's a late bloomer and looks like she's about eight, anyhow. (Kawamura is very feminine in a neatly dressed, 'ever gentle and low' sort of fashion, so it surprises people when it turns out that she has excellent shoulder definition and fetches and carries even the heaviest things for her father and is also completely impossible to intimidate. Which is not mentioning the results of tennis rackets. Fuji is smiley and cheerful and sort of disturbing and considers bras a waste of time. Just on that edge of butch.)

It's one of those interesting things, especially if you want to keep the relationships fairly intact. Particularly since you're right, there's all the social gender aspects - I think it's kind of fun to try to keep people's place on the social gender continum roughly the same, if possible. So a character who, as a guy, is proud of his masculinity, is, as a girl, proud of her femininity. And people who just kind of wish it'd all go away still just kind of wish it'd all go away.

Speaking personally.