Yuma Isogai, the male class representative of Kunugigaoka Junior High School’s Class 3-E, sports spiked dark brown hair with distinctive hair antennae and carries a humble, approachable demeanor. His family faced financial collapse after his father’s death in a traffic accident during his first year of middle school, forcing him to support his ailing mother and two younger siblings through part-time work—a violation of school rules that led to his transfer to Class 3-E.

A natural leader, he unites classmates through strategic ingenuity, exemplified by his orchestration of Class 3-E’s underdog victory in the Athletic Festival’s bo-taoshi match against Class A. Drawing inspiration from historical tacticians like Hannibal of Carthage, he leverages teamwork over brute strength. Academically, he dominates social studies and geography, securing top school rankings, though biology remains a challenge.

In combat training, he excels as the top male knife wielder and second-best marksman. His leadership balances class dynamics, mediating conflicts between peers like Karma Akabane and rivals such as Asano Gakushuu. Post-graduation, he oversees the class’s government reward, allocating funds to charity, education costs, and preserving their mountain classroom. Seven years later, he spearheads renovations to honor their shared history.

Loyalty defines his relationships: childhood friend Hiroto Maehara aids him during crises, while co-representative Megu Kataoka bolsters his confidence during moments of doubt. Despite financial strain, his humility and dedication to family and peers endure, guided by his creed of collective effort: *“If the cuckoo bird won’t sing, let’s all sing.”*