The protagonists of the novel learned musical instruments in the same cultural palace when they were young. During the 30th anniversary of the school, they were organized to perform together. Since then, they have known each other and have become very good friends. The father of Fu Xuankai, the eldest of the four, passed away two years before they met. This made him very mature, stable and understanding of the world at a young age, but he also lacked the liveliness that should be expected at this age. . . Twelve years later, they are still very close, but as the cause of the death of the eldest father fourteen years ago is revealed bit by bit, they begin to fall apart. It turns out that there is a surprising secret hidden behind their fourteen-year friendship, which leads to more stories. . . .