Tell me! Mother Chisato's dangerous home education

Tsutomu usually only masturbates and shows no interest in anything else. Chisato couldn't help but worry about his son. One day, Tsutomu came home from school with an injury, and when I asked him why, he said, ``I got a 0 on the test, and people laughed at me, so I got angry and we got into a fight.'' Concerned about his son's fate, Chisato decides to use his own body to teach Tsutomu studies so that Tsutomu will not be in any worse trouble.