Yuu works out with a balance ball given to her by her son to prevent back pain. She then loses her balance and climbs onto her son. The son, who felt a woman in her mother's sweaty body, ran away in shame. After that, her husband comes home and she hugs Yu saying "It's erotic". She was a married couple after a long time and she felt good, but she wanted more of Yu's body. She then Yu she came to masturbate. She saw it and her son got excited and hugged him...
