Nakano Koenji attends high school alongside Komaba Ikenokami and Takao Asagaya, actively competing as a volleyball player. Her tsundere demeanor presents a prickly exterior that conceals deeper emotions. Secretly, she harbors romantic feelings for childhood friend Asagaya, though never voicing them in daily interactions.

Nakano becomes entangled in a critical incident when Asagaya uses an experimental device to possess Komaba's body. Under Asagaya's control, Komaba's body initiates intimate contact with her. Mistakenly believing Komaba acts of his own volition, Nakano interprets this as genuine attraction. During the encounter, an emotionally vulnerable Nakano confesses her long-hidden affection for Asagaya—prompted by Asagaya himself, still inhabiting Komaba's form, who directly questions her about these feelings.

The confrontation escalates when Komaba's brother arrives unexpectedly with companions, resulting in further non-consensual acts while Asagaya remains trapped in Komaba's body. After Asagaya returns to his own form, he reveals the possession and cruelly mocks Nakano's heartfelt confession. Discovering the deception and exploitation of her vulnerability, Nakano retaliates violently against Asagaya, physically striking him for the emotional betrayal and violation. This sequence defines the extent of her character development in official media.