OBA-009 Your son is not a virgin. Kumiko Shinzawa.

"Only for a few days after the renovation..." Kumiko willingly agreed to let Naoto, the eldest son of the Ueda family, live next door. The next day, Naoto visits the Niizawa family accompanied by Yuko, the daughter-in-law of the Ueda family. Kumiko's son Junpei couldn't hide his joy at the beginning of his new life with Naoto, but... However, Kumiko couldn't forget the words Yuko said. That is to say that Naoto is a "virgin". Kumiko, who is curious if Naoto is really a virgin, takes a bold action after taking a bath.