Jang Jae Yul is a famous mystery novelist and popular radio DJ who suffers from OCD. When he meets Ji Hae Soo, a first-year psychiatry fellow at the hospital where he is being treated, they help each other work through their deep-rooted emotional issues. But how will Jo Dong Min, Hae Soo's senior colleague and first love, and Lee Pul Ip, Jae Yul's girlfriend, feel about their growing closeness?