Yuriko ends up helping out a middle-aged man called Kayama, who has just come in for sales. She feels a sense of familiarity with him due to his gentle personality, but... One night, while the two of them are working overtime alone, they are suddenly hit by lightning. Yuriko, who is afraid of thunder, instinctively clings to him... A power outage plunges the office into darkness, and Kayama, excited by her innocent reaction, can't help but push her down. Despite her refusal, Yuriko is carried away by the pleasure of being passionately desired in the darkness, and in the darkness she lets herself be carried away by the pleasure...