Do Yong-Sik (Yoon Si-Yoon) is 31-year-old man with some troubles. He has prepared for the civil service exam for years. During this time, his physical appearance has deteriorated, with a now big gut. Do Yong-Sik is also impotent. He decides to go to a urology clinic to address his impotency. There, Do Yong-Sik meets his first love Lee Ru-Da (Hani). She works at the clinic as a urologist. Meanwhile, Lee Ru-Da is a proficient doctor with a beautiful appearance and comes from a wealthy family background. She is dating Do Ji-Hyeok (Park Ki-Woong), who works as a psychiatrist. Her boyfriend runs a psychology counseling clinic. He is conceited when it comes to himself, which rubs Lee Ru-Da the wrong way. To lower his overconfidence, Lee Ru-Da brags about her first love Do Yong-Sik to her boyfriend. One day, her first love Do Yong-Sik appears in front of her. His appearance is totally different from their past.