Are You A Boy Or A Girl?

Yes.

This happens a lot with characters who wear something over their face that shields their identity, have faces and body figures that aren't masculine or feminine, and who just don't have straightforward appearances as a whole. One of the most popular examples of this is Metroid's Samus Aran, who was a Guy-Mistaken Girl. The gender reveal of people could shock many people in both fiction and in real life.