Ribbon no Kishi

Princess Sapphire is born with both a boy's heart and a girl's heart, but the laws of Silverland forbid a woman from inheriting the throne. To protect the kingdom from the scheming Duke Duralumin, her parents raise her publicly as a prince while hiding her true identity.

The trainee angel Tink is sent to retrieve Sapphire's boy heart, yet she refuses to surrender the strength it gives her. Her double life grows even harder when she falls for Prince Franz of a neighboring kingdom. Between court conspiracies, dangerous enemies, and the conflict between how the world sees her and who she truly is, Sapphire must defend both her throne and her freedom to choose her own life.