The butler-in-debt Hayate Ayasaki decides to help his master Nagi Sanzenin train to run in an upcoming track competition held by her school. However, Nagi isn't athletic at all, causing her to collapse after running barely 50 meters. Her head butler Klaus decides to make a bet: Either Hayate will help Nagi get in shape for the competition, or Klaus will fire him. Nagi responds by proclaiming her confidence in him that she will win first place in an event. Hayate is also interested in winning the competition, as he hears that the prize is 150 Million Yen, enough to clear his debt.
Thus, Hayate has to do quite a lot of work to get her in shape before the day of the freestyle marathon, while almost the entire main cast is either competing in or interfering with the race. Hinagiku and her hangers-on are running in several different events. When Hayate tries to find out which event she's not running in for Nagi, Hinagiku immediately catches on, and responds that she's competing in all of them. So Hayate decides to go where Nagi has the best chance, the Freestyle Marathon. Yukiji overhears the part about the prize, and sets off to find a partner for the marathon so she can win the money and spend it on expensive hard liquor.
Maria and Hayate both give Nagi a pep talk, and she decides to stop complaining and train hard for their sake. Then the day of the race finally arrives, and Nagi and Hayate enter as a team. Saki inexplicably offers some commentary at the mic stand, though she does mention that she only arrived at the race to deliver a lunch to Wataru. Hayate gets so wrapped up in his speech to Nagi that he forgets to notice the race has started. Yukiji rockets to the head of the race at first, practically dragging the PE teacher behind her, but they run straight off a cliff from going too fast. Meanwhile, Nagi quickly starts to lose her breath, and Hayate feels he has no choice but to carry her in his arms if they want to win. Nagi blushes at the sentiment.
Hayate runs into trouble along the path. First, the rival combat butler Himuro tries attacking him with sharp roses while his master Taiga throws some rose petals in the background. However, they are quickly interrupted by a superheroic duo of maids who look suspiciously similar to Maria and Saki. Taiga and Himuro simply walk away from the crazy scene while Hayate and Nagi continue forward. After an awkward pause, the maids quietly declare victory. Hayate then runs into other rival combat butler Kaede and his master Koutarou, who appear to threaten their progress. However, Kaede gets annoyed by his master's attitude, and beats him senseless with his shinai while Hayate and Nagi simply slip past them.
Finally, Hayate runs into Hinagiku and her partner, who have stopped to catch a second wind. Hayate puts his trust in Nagi to make it towards the finish line, and she obliges by running on her own, while Hayate stays to fight Hinagiku. Though she wields a shinai, Hayate simply dodges until he reaches a rope suspension bridge, causing Hinagiku to break down from her own fear of heights. They decide to watch Nagi's progress on a nearby monitor, and she appears to be a lock for the victory. Suddenly, Yukiji comes out of nowhere and crosses the finish line a fraction of a second before Nagi. Not only does Nagi come in second, but Hayate appears to have lost the bet with Klaus.