I discover my best friend's mother using the alias “Michiko” on a dating app. Replying under my own fake name, “Shingo,” I receive teasing selfie videos of her showing off her huge breasts and masturbate to them repeatedly. When she asks to meet, I agree despite the risk of recognition. She insists on preserving the secret identities of Michiko and Shingo, beginning a hidden arrangement behind her beloved son's back in which I can meet and creampie her whenever it suits us.