Tatsuya, who attends university outside the prefecture, chooses to live with his aunt. In this cohabitation filled with longing and anxiety, he struggles daily with uncontrollable desires. Though their relationship feels comfortable, numerous events unsettle his heart. One day, he deeply inhales the scent of his aunt's freshly removed panties, desperately trying to suppress his arousal. However, she catches him in the act, creating an awkward atmosphere. Unexpectedly, the aunt begins deliberately seducing him, rubbing his erect cock with her own underwear. In that moment, Tatsuya's heart is lost forever.