Kouji Sagara is a second-year student at Todo Academy and the founder of its pro wrestling club. Initially the club was not taken seriously, and its members were forced to train in a freshman restroom. The Executive Council, led by Mitsuomi Takayanagi, systematically beat the club’s members to pressure Kouji into joining the council, offering him a practice space and a budget in return for his loyalty. To protect his clubmates from further harm, he agreed, and the wrestling club became a subsidiary of the Executive Council with Kouji serving as one of its enforcers.

Despite calling himself the school’s most brutal executioner and operating under the masked persona of Saga Mask, Kouji is in truth a loyal, dedicated, and honorable person. He adheres rigidly to wrestling etiquette, even outside the ring; for instance, he will release a submission hold if an opponent claims to have touched the ropes, treating the real world as if it were a wrestling match. While wearing his mask he refuses to remove it under any circumstances, regardless of the trouble it might cause, because that commitment is part of his beliefs. Beneath his intimidating appearance lies a warrior’s respect for strength and a sharp tactical mind: he is able to deduce a counter to a newly seen technique after witnessing it only once.

His primary motivation is to protect the members of his pro wrestling club and to uphold the order of the academy, even if that means serving Mitsuomi. Over time, a deeper drive emerges through his encounters with Souichiro Nagi of the Juken Club. After being ordered to prevent Souichiro from intervening during an attack on the Juken Club at a bowling alley, Kouji was soundly defeated, but only after being promised a rematch. That loss sparked an intense desire to close the gap between them. He isolated himself in the Japanese Alps for three months of rigorous training, then returned to challenge Souichiro once more. In their rematch, Souichiro projected such overwhelming murderous intent that Kouji experienced a vivid illusion of being fatally punched, revealing just how far beyond him Souichiro had grown. This moment humbles him and reinforces his respect for Souichiro as a warrior.

In the school’s hierarchy, Kouji operates as a blunt instrument of enforcement. He was sent to punish Ryuuzaki for losing to Maya Natsume, an event he views as a direct assault on the council’s authority. During the bowling alley ambush orchestrated by Mitsuomi and Vice President Emi Isuzu, Kouji was assigned the job of blocking any escape rather than a direct combat role, a task he accepted out of duty but found frustrating. It was there he intercepted Souichiro and engaged in the fight that would alter his trajectory.

Kouji’s most significant relationship is with his club members, for whom he sacrificed his independence. Among the council, his connection to Mitsuomi is one of pragmatic loyalty, though he prides himself on keeping his word even if the system that binds him fails. His dynamic with Souichiro shifts from enforcer-versus-target to genuine mutual respect. He comes to admire Souichiro’s fighting spirit and sees him as a benchmark to someday surpass.

As a fighter Kouji relies on professional wrestling techniques rather than traditional martial arts, targeting bones and joints with precise, punishing slams and holds. His signature sequence, the Saga Special, chains a rolling turn into a German suplex, a jumping powerbomb, and finishes with a scorpion deathlock, all executed at remarkable speed. His other notable ability is the Muscle Bomb, a defensive technique that tenses his entire muscular mass to reflect the force of an incoming blow back into the attacker at the moment of impact, turning an opponent’s power against themselves. This move is so effective that Mitsuomi himself later adopts it. Together, these skills make Kouji a physically formidable and deceptively clever combatant whose appearance as a straightforward brute masks genuine ring awareness and resolve.