Thibaut is an internationally renowned conductor who travels the world. When he learns he was adopted, he discovers the existence of a younger brother, Jimmy, who works in a school cafeteria and plays the trombone in a small marching band. Everything seems to set them apart, except their love of music. Sensing his brother’s exceptional talent, Thibaut decides to remedy the injustice of fate.

Thibaut is a recognized conductor and pianist. While practicing for his next performance, Thibaut suddenly collapses. After discovering he needs a bone marrow transplant, he also learns that he was adopted and only now meets his younger brother, Jimmy, whom he never knew existed. Music becomes the bridge that connects the awkward relationship between the brothers. The title not only refers to a musical ensemble but also carries the meaning of 'walking together.' The film treats Thibaut's health crisis and Jimmy's struggle to gain recognition as a trumpeter like two different musical genres, which gradually merge at the conclusion to deliver a moving experience. (Huh Namwoong)