MKON-140 - My friend's bratty little sister is a total tease: Getting drained by a degenerate brat

Satoru gets stuck alone at his friend's house with his little sister, Karin. After losing a bet, he's forced to become her 'human chair'. Karin mocks his rising excitement, eventually turning the tables and pinning him down. What starts as teasing quickly spirals into a full-blown session of pure, unadulterated pleasure as she drains him dry, turning him into her personal sex slave.