To protect herself and her family, Hong Ra-on disguises herself as a man and counsels men on dating. Due to a love letter she wrote for a client, she meets Crown Prince Hyo Myeong. Ra-on is unaware that he is the Crown Prince, and Hyo Myeong is unaware that Ra-on is a woman. Soon after Ra-on is forced to become a eunuch by loan sharks, and the Crown Prince and Ra-on become interested in each other. As Ra-on tries to survive the palace and the Crown Prince navigates his journey to become king, will their love prosper?