There is a unique type of uke. I think I should make a separate post on this although I always sum up any other types.
I am starting to doubt if the makers do this as a サービスシーン[service scene] since I seem to come across this a lot lately. But well, come to think of it, I have seen this kind of thing for ages. Anyway, if you see a male character who really looks like a girl, or occasionallycrossdresses, he is going to be a 性別受け[seibetsu-uke]. 性別[seibetsu] means gender.
Upon hearing this, you might be thinking of 性転換[gender-bending]. But no. 性転換[seitenkan] is to change a character’s gender like Kyonko(boy→girl) or Haruhiko(girl→boy) in the Melancholy of Suzumiya Haruhi. However, 性別受け doesn’t do this. They are strictly boys no matter how much they look like a girl.
Then why is this necessary? Because if you change a character’s gender, he won’t be uke anymore. Here is another way to change a gender, 女体化[jotaika]. 女体化 is to womanize his body, I mean, to make him physically function as a woman. やおい穴[yaoi ana] is a good example. Either, やおい穴 might be necessary no matter what, though…However, those fans who love 性別受け do not want to change his gender, but want him to be a boy no matter how much he looks like a girl. Crossdressing is preferable because it makes him look like a girl much more (but he is still a boy). Usually, when a character crossdresses in the series, he would be embarrassed. Yes, that is what turns fans on. Hard to believe it? I don’t think I am explaining this well, so feel free to ask me if you don’t understand.
Then let’s see some example. If you have played Code Geass LOST COLORS, you must have seen Lelouch of trying a wedding dress. In this case, Lelouch is just wearing a wedding dress, not gender-bending. He is not acting like a girl, Luluko. Next is Fuchoin Kazuki in Get Backers. He is definitely a 性別受け because he really looks like a girl. The way he is also seems to be girly. But he is strictly a boy. Is Jubei really sure about this? Come to think of it, he cosplays a nurse in the series, and wraps his chest with a towel when he takes a hot spa with Jubei. なんで胸を隠す必要があるんだ? There is Tieria in Gundam oo. He also crossdresses in episode 8, doesn’t he? If nothing else, he looks like a girl!
Caught on, haven’t you? I already explained 女装少年[josou shounen], yes 性別受け has something to do with 女装少年. When such a shota-looking character crossdresses, he is going to be a 性別受け for sure. Ciel in Kuroshitsuji is a perfect example. His crossdressing killed some of my fujoshi friends actually. But remember, if a character crossdresses on purpose in the first place, he wound not count such as Watarase Jun in Happiness. Meanwhile, not only his looking, but the way he is seems to be girly shall make him 乙女受け[otome-uke]. Wolfram in Kyou kara maou?
If you want to bully your favorite uke-character, use 性別受け and humiliate him!