Even after passing puberty, the mother and son could not stop bathing together, ultimately leading to a physical relationship between the mother, Chiaki, and her only son, Kenji. However, once Kenji became a student preparing for exams, they set a deadline of 'until he passes' and stopped bathing together. Then spring arrived. Seeing Kenji lying around the house with no motivation after failing his exams, Chiaki suggested, 'How about we take a bath together sometime?' inviting him to bathe with her...
