After his father remarried the younger Asakura Ayane, Takashi suddenly found himself living with a beautiful new stepmother—and he couldn't hide his confusion. Every night, he was exposed to the couple's uninhibited intimacy, and Ayane's alluring figure became burned into his mind. Before long, Takashi found himself unconsciously watching her. Sensing his gaze, Ayane gradually closed the distance between them, carefully maintaining boundaries at first. One day, noticing something strange about Ayane as she left the house alone, Takashi decided to follow her—leading to an even deeper connection between the two.