Chiaki has raised her only son, Takashi, with just one female hand. Sometimes gentle and sometimes strict, Chiaki treated Takashi as a noble "mother", and Takashi also respected such Chiaki. However, such a mother-child relationship is fragile and will collapse. A few days after Takashi's remark, Chiaki witnesses Takashi and her lover having sex at home. Seeing her son's penis and her lover's vagina rubbing against each other, the "woman" in Chiaki wakes up ...