Ushio Toujou, a member of the school athletics team, defiantly resists participating in the marathon despite his athletic prowess. As part of the disruptive trio "mecha mecha mote te ru mondaiji sannin gumi" (MM3), his antics frequently clash with student council president Mimi Kitagami’s authority. Their dynamic intensifies when Mimi challenges him to a race, aiming to push him toward joining the marathon. This rivalry sparks an evolving connection, with their competitive exchanges slowly revealing unspoken mutual attraction.

Labeled a troublemaker due to MM3’s reputation, Ushio balances his casual defiance with an undercurrent of untapped potential, creating tension between his relaxed demeanor and the school’s expectations. His interactions with Mimi drive his growth, navigating resistance to gradual engagement in events like the marathon. The narrative traces his emotional maturity through these challenges, anchored in school life and the shifting dynamics of their relationship.