A recently hardworking, innocent girl from the J○ club returns home in her school uniform and bloomers. Her father, unexpectedly aroused by her showing off her large butt in bloomers, decides to mix a love potion into her drink in a desperate move. Under the effect of the potion, the girl's sensitive body becomes overly excited, leading to forbidden incestuous sex. Despite her mind resisting, her overly sensitive body cannot refuse and she ends up begging for her father's erect penis.