Choi Han Kyul, played by Gong Yoo, is the cocky son of a very rich family who runs a damaged food corporation. He doesn't believe in love and certainly doesn't want to get married despite his family's requests. On the other hand, Go Eun Chan, played by Yoon Eun Hye, is a 24-year old tomboyish female who gets mistaken as a guy quite often. She takes up every job possible — waitress, food deliverer, etc — and has the responsibility of taking care of her mother and younger sister. Eun Chan accidentally meets Han Kyul twice, once on a delivery and once during a robbery. During the robbery, Eun Chan's delivery motorcycle ends up being damaged. Han Kyul, not knowing that Eun Chan is actually a girl, decides to hire Eun Chan as a false "lover" so that he can escape the blind dates arranged by his grandmother. Meanwhile, Han Kyul's cousin, Choi Han Seong, is an established music producer and his ex-girlfriend Han Yoo Joo, who Han Kyul secretly loved for nine years, is a famous artist who studied in New York. The two were lovers for about 8 years but their relationship ended when Yoo Joo broke up with Han Seong. Two years after they separated their paths cross again when Yoo Joo returns to Seoul.
After getting an ultimatum from his grandmother, Han Kyul takes over a run-down severely damaged old coffee shop, later renamed Coffee Prince, to prove his ability, both to his grandmother and Yoo Joo. In order to attract female customers, he only hires good looking male employees. In a struggle with money, Eun Chan, whom Han Kyul has already mistaken as a boy, hides her gender identity to get a job at Coffee Prince. Soon feelings start to spark between Eun Chan and Han Kyul. Because he's unaware that Eun Chan is a girl, Han Kyul starts to question his sexuality.