Yang Mu and Leng Xuan were tourists from different parts of the world, passers-by who had no contact with each other, but fate refused to let them go. Whether it was bad fate or true love, no one could explain. Yang Mu regards Leng Xuan as his closest brother, but Leng Xuan regards Yang Mu as the love of his life. In order to repay the debt, Leng Xuan taught himself to write lyrics and arrange music; in order to repay the debt, Leng Xuan broke up with his father; in order to repay the debt, Leng Xuan had no choice but to agree to his father's request; in order to repay the debt, Leng Xuan had to choose to give in; in order to repay the debt, Leng Xuan exhausted his last talent... In the end, Yang Mu returned to the music scene and used his life's love songs to repay the debt.