April. Uta, a freshman, is starting high school and aims to join the light music club. However, when she sees the glamorous boys and girls of the light music club chatting away, her extremely negative personality makes her hesitant to take the first step.

Uta struggles with her first a cappella practice. Meanwhile, a new member candidate found by club president Airi becomes a hot topic. All the club members go out to recruit her to take on the role of "voice percussion," a unique part of a cappella.