When I first saw Yukimura in Haganai, Yukimura is actually a boy, according to Wikipedia. He crossdress as a girl, but he wants to show more masculinity. It is true ? But I think that I'm right.

You have it reversed, Yukimura really is a girl. She's a girl who truly believes she's a guy, who got trolled by Yozora to 'crossdress' as a girl. In other words, a double reverse trap.

Cyberbeing said:
You have it reversed, Yukimura really is a girl. She's a girl who truly believes she's a guy, who got trolled by Yozora to 'crossdress' as a girl. In other words, a double reverse trap.

But we don't know if Yukimura is a guy or a girl. According to Wikipedia, they use the word "he" and "his". It is revealed that's she's actually a girl, according to latest events.

MisaoFan said:
But we don't know if Yukimura is a guy or a girl. According to Wikipedia, they use the word "he" and "his". It is revealed that's she's actually a girl, according to latest events.

We knew. The author said so in vol.5 (iirc) of the novel.

wasn't anyone ever told you you can't trust everything searched on wikipedia (because any user can change/edit info on that site) so try to broadly search with multiple search engines like google.com, yahoo.com, ask.com, jeeves.com, etc. to get more definitive/conclusive answer to your inquiries