In the apartment of office lady Hikaru, who works in debt collection, hidden cameras have been installed everywhere. A stalker watches her private life every time she visits to collect payments. One day, she is violently raped as payment and forced to endure it on the spot. Later, at another collection site, she encounters an even more dangerous gang rape. Suddenly, the stalker appears and begins to "rescue" her. As oil and lotion play intensify, Hikaru grows increasingly aroused. Possessive dynamics deepen gradually, leading to new excitement in the fourth installment!