Jang Jae-yeol is a best-selling author and radio personality. He is playful and a little pompous, and he also has obsessive–compulsive disorder. Ji Hae-soo is in her first year of fellowship as a psychiatrist. Hae-soo has a negative outlook on love and relationships in her personal life, despite being driven and ambitious professionally and caring towards her patients. Once Jae-yeol and Hae-soo meet, there is a great deal of conflict between them due to their strong personalities and intransigence. But gradually, their quarreling transforms into love, and they realize how compatible they are. Jae-yeol and Hae-soo seek to cure each other's deep-seated traumas; however, their budding romance suffers a setback when they discover that Jae-mental yeol's health difficulties are more severe than they had previously believed.