The narrative revolves around five Japanese teenagers who have outgrown their childlike perspectives but are not yet adults. Wakana Sakai used to take music lessons before withdrawing after losing her mother. Konatsu Miyamoto is an optimistic girl with a passion for singing and often attends the vocal club after school. Sawa Okita is a spirited archery enthusiast who aspires to become a horse rider. Daichi Tanaka, a member of the badminton team, frequently arrives late and lives with his college-going sister. "Wiin," who has recently transferred from Austria after 12 years abroad, joins Wakana's class during their final summer in high school. Through music, these five individuals come together as an ensemble during their last year of secondary education.