Shiori Sakura occupies a distinct social position at Nankai Academy as the chancellor's daughter. She remains perpetually accompanied by her close companion and follower, Nozomi Itou.

When the investigation into Professor Yuko's murder unfolds, Shiori becomes the focus of a male student group. They ambush her in a gym storage room, binding her wrists and gagging her before sexually assaulting her while documenting the act—a method they term "punishment." Afterward, she is left partially disrobed and weeping in profound distress.

During the assault, the attackers uncover a concealed microphone on her person, suggesting possible information-gathering activities. The exact purpose behind this surveillance remains unspecified. This discovery introduces additional complexity to the violation as it occurs mid-assault.