Kawai Tomoki and Komori Yukino, a new couple in college, unexpectedly get a flat tire during their date. They find themselves seeking help and end up at the Black Rose Mansion, a mysterious place. Once they arrive, they meet Mamiya Mari, a charming and beautiful woman who convinces them to stay awhile. While in the mansion, they come across Takamizawa Rui, a flirtatious maid who wears a suggestive collar and cat ears. Tomoki and Yukino are unaware that their short stop will transform into a longer stay, where they unknowingly become victims of a strange, lustful holiday.
The more time they spend in the mansion, the more Tomoki and Yukino sense that something is amiss. They find themselves entangled in a world of temptation, where Mari and her companions allure them with indulgence and hedonism. Eventually, they encounter various taboo and erotic situations, leaving them lost in a world of sexual pleasure. However, they are unaware that they are now at the mercy of their sensual hostesses and their twisted desires, trapped with no escape in the mysterious Black Rose Mansion. What will happen to them?