50-year-old Rumiko's husband is so busy with work that their marital relationship has all but disappeared. She spends her days relieving her pent-up desires by herself. One day, her son accidentally discovers her in the act. Overcome with arousal, he can no longer suppress his urges and moves in on his mother without regard for morality or ethics, driven purely by instinct. Overwhelmed by the long-forgotten sensation of being desired as a woman, Rumiko is shattered—and begins to transform into someone different, twisted in some way. This shocking turn of events will drastically change her life forever.