With her husband away on a work assignment, Ritsuko (a pseudonym) lives alone with her son, who is preparing for his entrance exams. Unable to resist the masculine scent emanating from her son's body as he enters puberty, she begins working part-time as a nurse. One day, while caring for her son who has fallen ill, Ritsuko attempts to wipe his body and removes his clothes—only to witness a shocking sight. Her son is wearing her soiled panties and has an erect penis. This sight deeply shakes Ritsuko, awakening a long-suppressed desire within her that surges forth, pure and uncontrollable.