Hibiki Amamiya, a volleyball player working at a company, often ends up working late due to unfamiliar computer work... Then, suddenly a heavy downpour! Left behind at the company with her senior colleague, Amamiya reluctantly agrees to let him stay at her place. "Are you sure you're keeping your cool, senior...?" She knows it's wrong, but her colleague's innocent, perky breasts drive her crazy. "Don't you think it's wrong? What if your wife finds out... Ah, it feels so good..." Unable to resist the temptation of the young OL's wet, angular, and voluptuous breasts, the man ignores his wife and starts teasing her relentlessly, planting his seed inside her.