Life is like a piece of music with twists and turns. Who is the main melody in your song, and who are the dispensable notes? Guan Heng, a girl with great musical talent, participated in a singing talent show after the death of her friend Zhou Xiaodong, and met Li Mo, a bridge designer who Zhou Xiaodong was thinking about before his death. In Li Mo's eyes, everyone including himself is a small musical note. He seems to be gentle and modest in dealing with others, but in fact he has a cold personality. He never plays with life, but he doesn't take it seriously either. Guan Heng accidentally became the main theme in his life. Firstly, he owed Zhou Xiaodong a favor, and Guan Heng was the most important person to Zhou Xiaodong. Secondly, he really didn't understand how there could be such a person in the world, who had extremely high musical talent, but was stuck in life, clumsy and stupid, and was bullied and used by others without even trying to hide... Fate has arranged it like this. Among millions of people, let me meet you. I love you and spend all my life...