Your son is not a virgin.

Mika, the wife of the Matsushita family, and Yuki, the daughter-in-law of the Kikuchi family, who are neighbors and in the same situation as their husbands who are away on their own, have been close friends on a daily basis. One day, Yuki's husband falls ill, so Yuki's son Masayuki is left in the care of the Matsushita family. Before leaving, Mika was told by Yuki that Masayuki was a "virgin" and couldn't hide her interest in Masayuki. A few hours later, Mika will give Masayuki an unforgettable brush stroke experience for the rest of her life...