Kenichi and Yoshino are lured to a mysterious mansion after winning a prize from a strange software program. While the stay begins with luxury and passion, Kenichi soon notices an unsettling atmosphere and the provocative behavior of the estate's residents. After discovering a manual on S&M training and receiving a cryptic call about "feral souls," Kenichi is drawn into a dark world of submission and dominance where the line between pleasure and punishment blurs.
Kenichi continues his stay at the mysterious mansion, where he is bewildered by the women's intense desire for punishment and humiliation. After a strange encounter with the nurse Michiru and the servant Terumi, Kenichi is given Yoshino as a "present" to discipline at his will. Despite his initial hesitation, Kenichi eventually succumbs to the mansion's perverse atmosphere, discovering Yoshino's true masochistic nature as he begins to embrace his own hidden urges.
Kenichi discovers the dark secrets of the mansion and his own sadistic impulses while participating in the torture of Yoshino. The power dynamic shifts when the family patriarch, Ganji, names Kenichi the new master of the house, granting him absolute authority. Kenichi proceeds to break Anna and her mother through brutal humiliation, forcing Anna into total submission as his slave just as a new set of unsuspecting guests arrives at the estate.