A woman comes to a hot spring with her husband and father-in-law. She had no idea that what was supposed to be a peaceful family trip would become the stage for an NTR affair by her father-in-law... The woman is drugged with an aphrodisiac for dinner, and is unable to resist her burning body, gradually becoming a lewd woman. She becomes aroused in the bathroom, in the building, and anywhere else, and finally becomes a sex slave, sucking her father-in-law's raw dick and begging for him to cum inside her while her husband sleeps...