Nao, whose hobby is jogging, feels lonely as her husband's physical strength and sexual desire decline. At that moment, her body becomes hot and throbbing as she sees the passionate gaze of her neighbor, Oki, staring at her. While her husband is out, she invites Oki over and accepts his humiliating play. "If you do what I say, you'll experience even more lewd thrills," he says, and Nao is swept up in a whirlpool of pleasure.