Miyuki Ōnuma commands the volleyball club at Fujimi High School with an iron fist, her domineering leadership creating immediate friction as new members join. Initially resistant to collaboration, she enforces rigid expectations, clashing with protagonists through authoritarian tactics that prioritize control over cohesion.

Persistent challenges from teammates gradually erode her uncompromising methods, fostering a shift toward mutual respect. Her once-stern demeanor softens into measured guidance, reshaping her leadership into a collaborative force that galvanizes the team’s unity.

Upon graduating, she relinquishes her role to pursue academic goals, triggering a deliberate transition that empowers emerging leaders. This exit underscores her evolution from divisive figure to redeemed mentor, framing her journey as one of adaptability and growth within the pressures of competitive sports.