Set during the Joseon Dynasty, the story follows twins born to the Crown Princess Consort, who orders the death of the daughter due to superstition. To save her, the baby girl is secretly sent away.
Years later, Dam I, the twin daughter, returns to the palace as a maid. After her brother, Lee Hwi, dies in a case of mistaken identity, their mother persuades Dam I to assume his identity. As she keeps her distance from others, Dam I begins to develop feelings for Jung Ji Un, her first love and later her teacher from a noble family.