In Korea during the first half of the 1700s, Lee San (Junho) is a reserved young prince who strives for perfection. His father’s murder haunts him, even though it leaves him in a position to ascend to the throne once his grandfather—the cruel and ruthless current king responsible for the death of Yi San’s father—has died. He has resolved to become a benevolent monarch who will reform the laws when he ascends the throne, but the manner in which his father was killed has left a deep emotional scar. At court, he meets a young woman named Sung Deok Im (Lee Se Young). Yi San falls in love with her and tries to persuade her to become his official concubine. But Sung Deok Im is determined and free-spirited. However, she is also intelligent enough to realize that becoming the royal consort of the future king is a prestigious role, but one that would limit her freedom and likely bring her little joy. But Yi San’s love for Sung Deok Im is sincere, and she begins to realize that forming a union with him could ultimately benefit his troubled kingdom.