Ryuichi Sashima, a high school student shaped by bullying, neglect, and isolation, carries a childhood marked by a traumatic brain injury inflicted during a game with Chihiro—a friend who reemerges years later as a guilt-ridden classmate. Oblivious to the injury’s long-term consequences, Chihiro vows to atone by granting any request, which Ryuichi weaponizes to coerce sexual acts, catalyzing his shift from victimhood to predation.

His sexual dominance, termed “infallible in bed,” stems from biological anomalies: a combination of physical attributes and pheromones secreted from his genitalia. These traits—a conspicuously large penis and a pungent, intoxicating odor—evolve into instruments of control, fueling his vengeful crusade against those who tormented him, particularly women complicit in his suffering.

Methodically exploiting vulnerabilities, he targets individuals like Tsukino Tamana, a peer with a scent-based fetish, deploying Chihiro to deliver semen-infused stimuli. This calculated manipulation extends to a teacher and other classmates, whom he aims to enslave through psychological domination and physiological coercion. His tactics weave a cycle of retribution, blending guilt, pheromonal allure, and brute physicality to assert power.

Chihiro occupies a dual role as accomplice and casualty, their bond oscillating between coercive exploitation and a warped intimacy anchored in shared trauma. Though driven by vengeance, Ryuichi’s strategies prioritize raw sexual prowess over subtlety, relying on primal instincts rather than emotional manipulation to enforce submission.