Song of Du Qiu has appeared in different scenes several times: the first time it appeared in the form of an ensemble of strings and electro-acoustic instruments, accompanied by boys singing with a strong Japanese folk style, which brought distinctive characteristics of the times and a sense of rhythm to the film; When the United States really faced the sleeping Du Qiu, the theme song appeared again. At this time, the music is slow and lyrical, and the warm string music plays a melody full of tenderness. The theme song appeared for the third time when Du Qiu fled by plane, and was sung by a slightly sad unaccompanied boy. Then the trumpet and the steady synthesizer rhythm replaced the boys to enter the main melody of music, depicting Du Qiu's determination to swear to wash away grievances.