Riko Hoshino was enjoying happy days with her fiancé, but her relationship with her ex-boyfriend, a doctor, quickly turned problematic. Realizing he was a deadbeat, she decided to break up with him. However, one day, her ex tracked down her home and suddenly showed up. After being slipped an aphrodisiac, Riko lost all self-control and, even with her boyfriend returning home, couldn't resist—repeatedly indulging in relentless cowgirl sex, climaxing over and over in an NTR (cuckold) frenzy.