Rui, a mother who has raised her only son, Kouta, while suffering from economic hardship. In preparation for the cost of the exam, Rui starts a water business as a side job, but one day a customer asks for a physical relationship in exchange for a high reward, and he involuntarily complies. And Kouta happens to witness such a mother's terrible act. Kouta despised Rui, and it made him unable to suppress his distorted feelings for Rui in him.