The son who is right in the middle of puberty jerks off every day. Since he's at that age, there's nothing Reiko can do but watch. But one day, she finds out that the material her son uses for jerking off is an AV featuring a mature actress his mother's age. For Reiko, this means that a dick that gets hard looking at women like herself is right in front of her eyes. And it's a dick that gets hard over and over again, ridiculously full of energy... There's no way Reiko, who has always been horny, could hold back.
