This drama tells the story of a vampire, Park Ji-sang who works as a doctor in a hospital. Yoo Ri-ta is a hotshot heiress doctor, a star physician at the hospital and the niece of the board’s chairman. She’s snooty and cold, but highly capable, and accustomed to being the golden girl. Lee Jae-wook is their chief, an outwardly gentle, inwardly ambitious man who will prove to be their biggest adversary.

Kim Gwan-Chul used to work as an accountant, but now he works as a chief for a company. He is man who follows his principles and uses common sense. He also stands up for those in weaker positions.

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 Lee Young – future Crown Prince Hyomyeong. Hong Ra On is unaware that he is the Crown Prince and Lee Young is unaware that Hong Ra On is a woman. The Crown Prince becomes interested in Hong Ra On. His eunuchs become aware of this and attempt to get Hong Ra On to become one of them.

Kim Young Ho is a personal trainer for Hollywood stars. Even though he comes from a wealthy family background, he suffered a devastating injury during his childhood days. Now, he overcomes his problems with patience and stubbornness. Meanwhile, Kang Joo Eun is 33-years-old lawyer. She has struggled to support her family. Now, she is overweight and challenge her-selves for a diet.