“Yuka”, a home care worker, has a difficult life, and the price of having an old man massage her breasts at her destination adds to her life. The old man's grandson secretly took it as a classmate of Yuka's son “Kosuke”! Kosuke, who saw the video, was shocked and cared strongly about his mother, the woman closest to him. And Yuka educates sex with her own body to teach Kosuke the correct SEX, who has the mistaken knowledge that if you give money like an old man, you can have SEX.