This 问题 is EXTREMELY over asked and has a simple answer. In the anime, Crona is considered a boy. Some evidence that would be proving this is that in SOME episodes Maka refers to Crona as a "he" when she was talking about him to someone else. (I don't remember who she was talking to him about 或者 what episode it was but if 你 really wanna know go watch the entire series yourself and find out.) And also Medusa tells Crona in another episode, "... now go be a good boy..." And obviously as his mother, she would know his gender. Meanwhile in the Manga, Crona (sometimes spelled Chrona) is considered a girl, where there are pages where they refer to Chrona as a girl 由 saying "her" 或者 "she." (You can go to chapter 96 if 你 want, Maka and Soul refer to Chrona as a SHE plenty of times.) And also there are some intervies 你 can find over the internet where the writer of Soul Eater confirms that Crona (or Chrona) has NO gender at all. So basically Crona can be whatever 你 want him/her/it to be!
Actually, Crona is androgynous, meaning there's not really a clear distinction. Yes, in the 日本动漫 they call them a boy, but in the 日本漫画 there are no clear distinctions on whether they're a boy 或者 girl.
