The Dokusen series chronicles the complete sexual monopolization of the beautiful student, Tsumugi. It begins when her own boyfriend, Kyoshiro, makes a twisted contract with his rival, Kaoru. They enter a competition to see who can more effectively break and train Tsumugi into the perfect sex slave, documenting their depraved acts on a private website for others to judge. The series details her brutal initiation, where both men take turns violating her body. She's forced to deep throat their cocks until she chokes on their cum, her tight pussy is stretched and pounded relentlessly, and her asshole is gaped open for their raw pleasure. Tsumugi's degradation is the central arc, as she is systematically stripped of her will and transformed into a mindless receptacle for their seed, her every orifice claimed and repeatedly filled in a relentless series of hardcore, non-consensual encounters that leave her mind broken and her body drenched in semen.