Nanao lives with her husband, mother-in-law, and 24-year-old son. - The only complaint I have is that I haven't had sex with my husband for 20 years. - The only things I'm worried about are that my mother-in-law has recently started to get bored, and that my son is still a virgin. - A tremor struck such an ordinary family! - The obscene mother-in-law stole his virginity from her son, telling him, ``Grandma will teach you.'' - Nanao witnessed the scene. - She masturbates to get rid of her strange excitement, but she can't get enough of it and ends up touching her son's body!