Due to Hayate's most recent borderline test scores, Nagi gives him some time off to study. Meanwhile, Klaus sends a robotic butler built by Shiori, which looks somewhat like Hayate to fill in for him while he is studying. The robot, known as Thirteen, does an even better job as a butler than Hayate even could, which depresses him when he finds out. Hayate then tries not to get too worried when Sakuya tells him that Nagi and Thirteen get along well. As Nagi realized how jealous Hayate is, she is somehow enjoying his jealousy over her...