Yuriko finds herself helping Kayama, a middle-aged man newly assigned to the sales department, and soon warms to his gentle nature. One night, while the two are working overtime alone, a sudden thunderstorm frightens Yuriko into clinging to him. The office loses power, and her innocent reaction arouses Kayama so much that he can no longer restrain himself and pushes her down. Though she resists, Yuriko is overwhelmed by the thrill of being wanted so intensely and surrenders her body to the pleasure in the darkness...