The first time I was introduced to my boyfriend's sister, she took a liking to me... A girl approaches me while I'm sitting in the kotatsu! When her boyfriend isn't looking, she secretly fingers herself with fingers covered in aphrodisiac, and something strange happens to her body! Even though she hates it, she gets so anal that she begs for more aphrodisiacs to feel even better! Her reason is blown away and she becomes immersed in lesbian pleasure that she can't experience with her boyfriend!