After witnessing a brutal assault at a deserted train station, Murakami becomes obsessed with the violence rather than horrified by it. Driven by a dark impulse to recreate the scene, he begins stalking a girl named Luna. He eventually ambushes her at the unmanned station, initiating a terrifying cycle of predation.
Madate continues to blackmail Luna into submission using a recording of their encounter, but his predatory activities escalate when he meets Murakami, a man who shares his dark desires. Together, they lure Luna and another girl, Hikari, to a deserted station for a depraved partner-swapping session. As the exploitation intensifies, Luna begins to succumb to a twisted sense of pleasure in the danger, ensuring that the cycle of terror at the unmanned station will continue.