Driven by curiosity, female college student Arisa Misato visits her associate professor Tachibana at his home to assist with research. While inside, she hears unsettling moans coming from the second floor, leaving her deeply disturbed. After learning that Tachibana's younger brother has suffered from mental illness and remained shut in for over ten years, Arisa seizes the chance to investigate when Tachibana steps out. She heads upstairs and approaches a slightly ajar door, sensing that no one should be inside. But the moment she opens it, a thick arm suddenly lunges out from within—and drags her in. What awaits her is a sexual violence far beyond imagination. Her innocent and pure curiosity pulls Arisa into a mansion of rape madness. One shocking development after another shakes her to the core, driving her to the brink of madness.