In the dimly lit bedroom, two Japanese siblings, Ena and her brother, exchange furtive glances. Their parents' voices echoing from the living room, they know they're alone. Ena's heart races as she watches her brother's eyes linger on her body, her nipples hardening under her thin shirt. She feels a warmth between her legs, a sensation she's never experienced before. Her brother tentatively reaches out, his hand brushing against hers, sending electric shocks through her veins. They freeze, listening for their parents, before Ena slowly guides his hand under her skirt, teaching him the rhythm she craves.