Kozue is a middle school girl and an enthusiastic volleyball player. Her dream is to play for the Japanese national volleyball team. Throughout the series, she advances step by step from the school district league to the Japanese volleyball finals, and eventually to the international volleyball championship. However, the higher and faster Kozue climbs the career ladder, the more she is confronted with the dark side of success: excessive expectations, self-conceit, and envy are escalating into serious problems.