A shy Japanese virgin, untouched by any man, finds herself alone with her older brother in their cramped bedroom. As they struggle to maintain their virtue, she can't help but steal glances at his crotch, her curiosity piqued by the bulge she sees. He catches her looking and, with a mischievous glint in his eye, begins to tease her, slowly revealing his throbbing cock. She tentatively reaches out, her small hand barely able to grasp his thickness, as she explores her first taste of forbidden fruit.