Reiko is a single mother. She has worked hard to raise her son, forgetting that she is a woman. But now that her hard work is finally paying off, her tense Kokoro relaxes and her suppressed desires begin to overflow. It all started when her son touched her nipples while massaging her shoulders. Reaction to her abstinence awakens her to an ultra-sensitive constitution that orgasms instantly just by touching her nipples. Impulsively, Reiko crosses the forbidden line with her son, and the next day she goes to work without a bra, exposing her nipples.