Thirty-something Wife: Reward for Adultery (1995)

Sawano married Satomi, a distant relative of his boss at work, Fujimori. Fujimori has a wife named Akiyo, but also a mistress named Rio. Fujimori is being transferred, so he asks Sawano to take over his position so that Rio won't cheat on him while he's away. Sawano has a woman named Hagiyama Ayako, whom he keeps a secret from his wife. She is a seductive married woman. When Fujimori's wife Akiyo finds out about her husband's affair, she seduces Sawano to get revenge... This film, written by Futami Rei and directed by Fukamachi Akira, is a passionate drama that depicts the pleasures of an affair between a married man and a married woman.