Yuriko, who ended up helping a middle-aged man named Kayama who came in for business, feels a closeness to his gentle personality... One night, when they were working overtime alone, they were suddenly struck by a sudden thunder. Yuriko, who is afraid of thunder, instinctively clings to him... Due to a power outage, the office was plunged into darkness, and Kayama, aroused by her initial reaction, couldn't resist and pushed her down. While resisting, Yuriko was overwhelmed by the pleasure of being intensely desired and surrendered her body to the sensation in the darkness...