Sae, a beautiful daughter-in-law, lives with her useless father-in-law Shigeharu, who is vulgar, irresponsible, and fond of gambling. Shigeharu has his eye on the youthful and beautiful Sae, and he regularly peeks into her bath and steals her underwear to sniff it. One day, Sae's husband Makoto leaves the house on a business trip for two nights... Shigeharu sees this as his chance to reveal his true nature and attack Sae. He holds down Sae, who is desperately trying to escape, and thrusts his engorged penis into her.