well, Ichi, the girl pretending to be a guy (such as Utena) is based upon the story of Versailles no Bara, the first to ever do that (and actually, the old seventies manga behind many things in Utena) Originally, doing that to a female lead was done to be able to use the female lead in situations seen as improper for a woman (Japan is not only an homophobic country, it's also sexist...It's a beautiful country, but let's face it people, any country that makes you weird sailor suits to go to school has had a twisted unbringning) Nowadays, it's like you say, sorta mixed in with all the shonen and yaoi pile...makes for an interesting psychological perspective on things does it not?
By the way, love the icon.