As it is, this merely means gender-bending. In real life, someone who really wants to change the sex undergoes a surgery. No no no, that’s not what I am going to tell. Okay, if you happen to be a big doujin fan, or a doujin artist, you would be definitely sure of this. Yes, switch your favorite characters’ gender and let them make love, so you can create 性転換[seitenkan] or gender-bending.
Basically, this method used to be popular among BL fangirls who don’t want to see a favorite character having a sex with a girl (but die to see his own nudity!). Using this method, seme can be an uke, and there’s other way around. But after all, it’s 夢オチ[yumeochi]…Ugh, this is too typical. Having said that, this seriously requires viewers’ understanding. Sheer fans would hate it, so that this genre might be cliquished. Even if you come across such a blog or video, a note says in advance for sure.
Meanwhile, this method is used to make a joke. For example, such a bishoujo gets a muscular body (but her face still remains)! Or else, Jojo (Jojo’s Bizzare Adventure) or Kenshiro (The Fist of the Northern Star) has a ribbon in his hair or wears over knee socks (yes, zettai ryouiki for sure!).
However 2006 onwards, there has been a lot of decent gender-bending fanarts. They just enjoy gender-bending, so it’s not even necessarily yaoi. It’s more of a parody, yes, here’s the most famous parody series, 性転換エヴァンゲリオン[Gender-bending Evangelion] which all the characters are gender-benders. I must say this genre has been in the mainstream.
Needless to say, this is definitely popular among cosplayers. Well, a better saying is crossdressing though. The intersting thind is that there are a lot of cosplayers who even do Suzumiya Haruhiko series[gender-bending Suzumiya Haruhi]. So girls can cosplay Kyonko or Itsuko, and guys can do Haruhiko or Yuuki. Either way, I won’t do this though.