An amateur girl is challenged to answer quiz questions while in a humiliating state—hands tied behind her back and a vibrator firmly attached to her crotch. She has 10 minutes to correctly answer 10 questions to win a large cash prize. However, the vibrator's nasty vibrations break her concentration, causing repeated wrong answers and ultimately a time-over. The condition for a second attempt? No panties, direct attachment of the vibrator, plus additional erotic pranks! Though the girls aim for the prize money, they become increasingly aroused by the direct-contact vibrator and lewd teasing, resulting in all five failing their challenges. As punishment, they immediately receive rough sex!