A marathon is coming up at Nagi's school, and Maria and Hayate want her to participate too. Nagi makes a bet with Klaus, where if she can get in first place in one of the races, then that would prove Hayate's worth as a butler, but if she cannot, then Hayate will be fired. Hayate trains with Nagi the next two days, and the day of the race the two get off on a slow start. Before long, Hayate must carry Nagi throughout most of the race, and faces a few enemies along the way impeding their progress. After running into Hinagiku, Nagi goes on ahead, but just as she is about to win, Hinagiku's older sister Yukiji beats her to the goal, winning the 150 million yen prize.
ナギの恩義に報いるため、日夜一流の執事となるべく努力しているハヤテ。そんなハヤテとナギが、白皇学院五つの伝統行事の一つ「マラソン自由形」に挑むことに。しかし、ナギは50メートルを長距離と言いきってしまうくらい、極度の運動オンチ。果たしてハヤテはナギお嬢様を無事ゴールに導くことが出来るのか!?
