Kai (Kwon Sang-woo), a radio producer abandoned by his parents since childhood, and Luo Lin (Lee Bo-young), a lyricist who lost both parents in a traffic accident, live together like family, friends and lovers, filling the empty seats in each other's lives. But a terminal illness left Kai with only more than 200 days to live. He was reluctant to leave Luo Lin alone and decided to hide his illness and find a man who could entrust her life to her. The successful, gentle and considerate dentist Zhu Huan (Lee Beom-soo) appeared at the right time, and Kai decided to make him the best person to take care of Luo Lin. Zhu Huan fell in love with Luo Lin at first sight when he first met her, and Luo Lin seemed to have a good impression of him. Everything was in Kai's plan. Luo Lin and Zhu Huan developed their feelings smoothly and reached the point of talking about marriage. Kai personally selected a wedding dress for Luo Lin, and walked to Zhu Huan step by step in the church with nostalgia and sincere blessings. In the end, Kai left the world without any regrets, and in fact, the story is much sadder than what is written here...