In Naruto, Haku is a rogue Ninja that fights along Zabuza. He has a sad history of death and mistreatment that I won't treat here.
In any case, the Haku's peculiarity is that although he looks/behaves/dresses like a woman, he is a man. But not all sources agree with this, so... Is Haku a man or a woman?
Is there a reason for the first part in my spoiler? Or is it just a plot device?
If your answer contains something that appears or is explained after the Bridge battle with Team 7 (as far as Haku is concerned), please use a spoiler.