At Kōdo Ikusei Senior High School, an elite institution featuring cutting-edge facilities, nearly all graduates advance to top universities or secure promising careers. Students enjoy freedom in personal expression through their appearance and possessions, cultivating an image of educational paradise. The reality, however, reveals a rigid hierarchy where only the school's most superior students receive genuine treatment and recognition. Kiyotaka Ayanokōji occupies D-class, the institution's designated repository for academically inferior students. His placement stems from deliberate underperformance during entrance examinations, a calculated decision made for reasons of his own. Upon forming connections with classmates Suzune Horikita and Kikyō Kushida, Kiyotaka's circumstances undergo a dramatic transformation.