Waka is a single mother. Her only son Kaito is growing up, and it seems her time raising him is coming to an end. Still in her prime, Waka has found a new boyfriend and is enjoying being a woman, but when she tells Kaito of her intention to remarry, he becomes enraged and rejects her, saying, "Don't take my mom away!" This is the opportunity for her boyfriend to leave her, and Waka, in her disappointment, turns to alcohol... Waka suddenly becomes gloomy and drunk, but she finds joy and pleasure in her son's immature side and the part of him that he has become a man. Is it because she is drunk, has carnal desire, or is it her maternal instinct... She teaches her son, who needs her, about the female body, step by step, as a form of sex education...