After missing the last train at a company drinking party, new employee Sayu took advantage of the fact that his coworker's wife had gone back to her parents' house during an argument and crashed at his place. As soon as he got home, Sayu passed out, so he played a prank on him. Unable to wait any longer since Sayu showed no signs of waking up, he went ahead and inserted himself. Later, when Sayu suddenly dropped by on a day off and threatened him about 'that night,' he ended up being toyed with by the little devil of a new employee!
