Hong Ra On, masquerading as a man, offers dating advice to men. Through a love letter she penned for a client, she crosses paths with Lee Young, who is destined to become Crown Prince Hyomyeong. Unbeknownst to Hong Ra On, Lee Young is the Crown Prince, and he, in turn, does not realize that Hong Ra On is actually a woman. The Crown Prince finds himself drawn to Hong Ra On, prompting his eunuchs to try to recruit her into their ranks.