Asuka, the senior's girlfriend, appears to be a typical gyaru, but she's actually gentle and always considerate of her boyfriend. However, when she learns that he's away on a business trip, she can no longer suppress her longing for him. Though she feels guilty about betraying him, she's secretly been attracted to the senior for some time. Seizing the opportunity, she starts making advances toward him. Over the course of three days, the senior gives in to his desires and repeatedly creampie her. Their relationship grows increasingly intimate while her boyfriend is away.