The story centers around five Japanese high school students who are too young to be called adults, but who no longer think of themselves as children. Wakana Sakai once took music lessons, but she withdrew from music after losing her mother. Konatsu Miyamoto is a positive-thinking girl who loves singing and spends time after school at the vocal music club. Sawa Okita is a spirited archery club member who dreams of becoming a horse rider. Daichi Tanaka is a chronically late badminton team member...

The story depicts a young boy named Shuuichi Nitori who wants to be a girl, and his friend Yoshino Takatsuki, a girl who wants to be a boy. The series deals with issues such as transsexuality, gender identity, and the beginning of puberty.