A married woman in her fourth year of marriage. She lives with her husband's father. Her busy husband is often away on business trips, and the wife is frustrated by the lack of sexual relations and masturbates, but her father-in-law sees her doing so. One day, a delivery man from her affair partner comes and they have sex, but her father-in-law is watching again. Then, her father-in-law uses the fact that he witnessed her masturbating and cheating to demand sex with his voluptuous body. He threatens to tell her husband, and she can't refuse, so she opens her legs. Furthermore, she is raped at night by her father-in-law, who she hates, and is made to climax many times.