Takumi Mikami operates as the narrative's central antagonist and Professor Saki Azuma's boyfriend, concealing a profoundly manipulative and predatory nature beneath this facade. Labeled a "sadist and pervert of the worst calibre," he previously lost his teaching position after stalking a student. Following his dismissal, Mikami exploits Saki's emotional vulnerability and blind devotion to secure employment at her university. Within this academic setting, he resumes predatory behavior, targeting multiple female students for personal gratification. His exploitation extends further as he coerces Saki into actively using her position and trust to lure victims, including Harumi Shiraishi, Mao Sakurano, Minori Sakurano, Natsuki Arakawa, and Yukari Saijou. Mikami's background remains anchored in his prior misconduct and the escalation of his actions in the new environment, without narrative exploration of redemption, character development, or expanded backstory. Details regarding his appearance, specific dialogue, or presence in official media adaptations remain undefined.