Board Thread:Spoilers!/@comment-4877635-20130614170253/@comment-6175354-20130802202205

Gusey1397 wrote: I'm not intentially. Mulan poses as a man as in Ancient China, women weren't allowed to join the army. Therefore, she poses as a man. Yes.... in the original legend.

While it is a running gag, for people to think Mulan is a man. It was never stated, on the show, if she hid her gender while serving in the Army. OUaT is imfamous for twisting the tale, and that would be a pretty cool twist.