The Reason Why My Wife Got Prettier (2019)

Suspicious of his wife, Misako, Rintarou hires a detective to spy on her. The report he receives from the agency contains a picture of Misako in the act. Looking like an idiot, the guy in the picture is Kuroda. Rintarou calls both of them out. In return for looking the other way, he wants them to film a sex video…