Baek Joong-won once saved the vampire Ehwa from being burned at the stake by his fellow villagers. While attempting to escape together, Joong-won fell off a cliff, and Ehwa gave him her blood to save him from dying. Thus, Joong-won was also transformed into a vampire.
In modern-day Seoul, the 350-year-old Joong-won runs a luxurious wine bar in Gangnam District with Ehwa. Though she holds a torch for him, Ehwa can only observe and protect her friend from afar, as he has long closed himself to any new emotion. One day, Joong-won receives a letter from a former lover, a human he had broken up with 20 years ago without telling her the truth about himself. In her letter, the dying woman asks Joong-won to look after her daughter, Ji-woo.
After her mother's funeral, Ji-woo finds a photograph her mother treasured very much, and she searches for the man in the photo, her mother's long-lost lover. When she finds Joong-won, she assumes that he is the son of the man in the photo. As Joong-won spends time with Ji-woo, all his emotions which were frozen by time start to melt away, and the two fall in love. Ehwa has difficulty dealing with this turn of events. Meanwhile, a serial killer who sucks blood from his or her victims is on the loose.