“Where does this feeling of wanting to cheer for others come from?” At Eagle Saki High School, a prestigious institution preparing to defend its title at the national cheerleading competition, Mikumo Kanata from the cheerleading club had won a national championship during middle school and became a member of the main team in her first year of high school. However, due to a mistake during a competition, she has been unable to jump again. One day, Kanata sees a parkour high school girl, Ryoha, leaping between buildings. Alongside them are Shiine, an artistic gymnastics princess; Anzu, a half-Japanese girl returning from Brazil; her classmate, a yoga philosophy girl named Fuka; and Kanata's former teammate, a girl named Keika who is in a wheelchair. With differing interests, talents, and personalities, the members occasionally sing together, experience conflicts, perform short plays, and daydream… And when the pure desire to cheer for others resonates, the cheer represented by “balloon boom” transcends cheerleading and directly reaches people’s hearts. Could the cheers of these six high school girls from Gunma change the world?