Amidst the daily crowded train commute, Ai, Yumi, and Saki find themselves entangled in forbidden pleasures with a mysterious man. These secret encounters escalate from frantic groping to raw, intimate temptation, igniting desperate passions and craving. Surrendering to a shared climax of need and intense sensation, they weave a web of lustful ecstasy, forming an unbreakable, sensual trio bound by their most exposed desires.