Although unable to read sheet music, the young high school student Dai Miyamoto pours all his passion into the saxophone, practicing day and night, to become the best jazz musician in the world.

When, after graduating and arriving in Tokyo, he meets the virtuoso pianist Sawabe, they decide to form a band, the JASS, to be joined later by a drummer. Their goal: to play in the most important jazz club in Japan, the So Blue. Will they succeed?