Fritz und Friederike (1952)

Friederike was raised by her uncle like a real boy. She can ride, fencing, curse and drink and defeats a real cavalry officer in a chase race. She doesn't feel comfortable in the girls' boarding school her uncle is sending her to, so she escapes disguised as a boy and smuggles herself into a barracks. There she meets her officer again, who sees through her game and falls in love with her. And so Friederike discovers her feminine side after all.