Koichi Wakabayashi leads the jazz/blues ensemble Moss Green & B.B., poised on the brink of major success. He initially treasures trumpet prodigy Ryo Takagi ("B.B.") as essential to the band's breakthrough potential.

Wakabayashi explodes with outrage when Ryo abandons music for boxing after a crushing defeat by Jin Moriyama. Feeling profoundly betrayed, Wakabayashi views Ryo's departure as the destruction of his own dream of musical fame and expels Ryo from the band.

Following Ryo's exit, Wakabayashi plunges into profound despair. His emotional state spirals downward, marked by visible distress and increasingly erratic behavior as he grapples with the loss of both his musical aspirations and the band's promising future.