Daichi Ishizaki attends Advanced Nurturing High School, starting in Class 1-C and advancing to Class 2-C. He sports dark green hair and eyes. His distinctive modified school uniform—an unbuttoned red vest, purple shirt, green slacks, and magenta shoes—creates a rough, delinquent-like impression. His middle school past involved frequent fighting and troublemaking, earning him a feared reputation that carried into high school. Initially clashing with class leader Kakeru Ryūen, Ishizaki's perception shifted upon recognizing Ryūen's strength, evolving into steadfast loyalty. He serves as Ryūen's primary enforcer within Class C, carrying out orders even when conflicted. Academically, Ishizaki performs below average, with official evaluations rating his academic ability D- (21/100), physical ability C+ (60/100), thinking ability C (52/100), and social contribution D+ (40/100), resulting in an overall C- (44/100) assessment. Ishizaki displays a volatile and impulsive nature, often resorting to violence and confrontation. He initially antagonizes students like Ken Sudō and Kiyotaka Ayanokōji under Ryūen's command. Yet, he possesses underlying loyalty, honesty, and a developing sense of honor. Pivotal events foster his growth toward valuing teamwork and reconciliation, exemplified by supporting teammates during the mountain training camp race. His physical prowess makes him a capable combatant, though decisively overpowered by Ayanokōji during a rooftop confrontation in Volume 7. Involved in coercing Kei Karuizawa under duress during this incident, Ishizaki later expresses remorse and seeks to mend their relationship. Significant development follows the rooftop event; Ishizaki risks expulsion to prevent Ryūen from leaving school, cementing his dedication. Subsequently, he collaborates with Mio Ibuki in Volume 10 to enlist Ayanokōji and Honami Ichinose's aid in rescuing Ryūen from expulsion, leading to genuine trust in Ayanokōji. Throughout their second year, Ishizaki repeatedly attempts to recruit Ayanokōji into Class C, believing their combined strength with Ryūen would be unbeatable. He exhibits increased empathy, partnering with isolated classmate Takeko Nishino during the uninhabited island exam and seeking to protect Ibuki from potential expulsion. He also reconciles with former adversaries like Karuizawa and Teruhiko Yukimura, reflecting his growing emphasis on cooperation. Key relationships define his trajectory: unwavering allegiance to leader and strategist Ryūen; a close, communicative friendship with Albert Yamada despite language barriers; a camaraderie with Ibuki forged through shared missions; and a shift from hostility to respect toward Ayanokōji after receiving assistance. He also mends ties with Sudō, moving past initial conflicts.