In the eyes of Mosaic (Wang Zulan), an urban sketch artist suffering from ALS, people and things are "gradually freezing". He needs to collect some happy memories before his condition deteriorates completely. He has a crush on his elementary school classmate Shenxianyu (Cai Charlene Choi) since he was a child. He finally plucks up the courage to make a last wish: "Give me one day, be my girlfriend, okay?"