A sister dozes off in front of her brother. Her defenseless appearance arouses the brother, who knows it's his sister, and he starts masturbating. His naughty pranks escalate as his sister doesn't wake up. But when his sister finds out, she's shocked. Still, the kind sister can't bring herself to hate her brother, and says, "Maybe he's been holding it in for a while, so he's been tempted by the devil, right?" and offers to help him masturbate...!