Hayate tries to wake Nagi up, even if it means removing the matress from her bed. He then showed her a newspaper headline that says "High School Girls Ultra Quiz!! Must compete as a pair of best friends". At first, Nagi wasn't interested, but when she witnessed a winning prize, which is a trophy, she decided that she will be in a quiz tournament. Nagi tried to call Sakuya so that she can be her partner, but finds out that Sakuya is on Osaka and cannot compete. She also finds out that Isumi being her partner is out of the question. Maria asked Nagi if Hayate can be her partner while wearing a high school girl uniform, but lucky for him, he got away to search for Nagi's "real" partner. Meanwhile, Ayumu read the same headline and witnessed another winning prize, which is an all-you-can-eat coupon at the "shabu-shabu" restaurant. She imagined if she invited Hayate to eat the steaks together, so she wondered if she can ask him personally, if she wins. Ayumu starts running while wondering who will be her partner, until she bumped into Hayate and fell to the ground. Hayate now have a perfect opportunity, so he held Ayumu's hand and asks her if she could be a partner for the quiz tournament. Ayumu accepted his request, only to find out that she will be competing with Nagi.
The 4256th High School Girls Ultra Quiz tournament is about to begin, and this tournament is hosted by the narrator himself, who revealed his name "Mikiri Teruo", only without showing his face, and Abe Maou, the demon from episode 10, as a co-host. Then, about ten-thousand pairs have assembled from around the nation to compete in a quiz tournament, including the pair of Aika and Chiharu, and ironically, the pair of Nagi and Ayumu. Nagi insults Ayumu by saying that she would rather win alone, partner or no partner, but in her thoughts, Ayumu calmed down. Nagi and Ayumu each looked forward to win different prizes, Nagi wants to win a trophy for its resemblance to Hayate, while Ayumu wants to win a coupon so she can go out with him. Hayate, as part of the crowd, saw both Nagi and Ayumu from far away facing each other. As the tournament begins, the first stage is a "True or False" Quiz. Each pair must go to the panel when they think it is the answer, and any pair who gets the wrong answer will be eliminated. For the first question, Ayumu thinks that the answer for finding the Ishikawa Station is true, but Nagi dragged her to "false". And for that, the correct answer was "false", and both Nagi and Ayumu are safe. For the second question, Nagi thinks that the answer for chimpanzees and pandas is false, but Ayumu dragged her to "true". And so, the correct answer was "true", and Nagi and Ayumu are safe again. The third question is about the temperature of "warm" Japanese sake, and since none of the pairs moved, they must answer that question, "Who Wants to be a Millionaire" style, only with their life-lines though. Nagi and Ayumu called someone who knows that answer on the telephone, and from the crowd, Hayate thinks that they are calling him, but it turns out to be Maria, from the Sanzenin mansion. Maria tells the both of them that the answer is false, and after that, Nagi and Ayumu went to "false", which is considered a correct answer.
The remaining pairs move on to the second stage, and it is called the "Scatter Away Quiz". Each pair must pick up a quiz that gets scattered from the sky, mainly from the blimp, so they can answer one question correctly in order to move on. Nagi went to pick up the question without Ayumu's help, until she tripped and gets a cramp on her leg, unable to move for a while. Ayumu picks up an card and shows it to Abe Maou, only to find out that it is a false card. So Ayumu went to find the question card, yet she still found the false cards again and again. Nagi stands up and both her and Ayumu still argue about the prizes, and Hayate, but when they noticed that their time is running out, they picked up the card and shows it to Abe Maou one last time, which she teased them about getting a false card. Mikiri Teruo asked them a question about the cost of riding the Yamanote line for one station. Nagi tried to answer the question, but Ayumu stops her and answered the question, in which the ride cost 130 yen as of 2008. The answer was correct as Nagi and Ayumu, along with the remaining pairs, move on to the third stage, and it is called the "Break Out of a Sealed Room Quiz". Each pair must find a way to get out of the room in order to answer the question. The door was locked, as well as the window, and there is no hole in the floor. Ayumu threw an object to break the window so that she can get out, only to find out that she and Nagi are in the skyscraper. Ayumu panicked, but Nagi solved the puzzle of how to get out of the room. Afterward, the next question is about the first game console sold in the world back in 1972. Ayumu tried to answer the question, but Nagi stops her and answered the question, which is "Oddysey". The answer was correct, and Nagi and Ayumu moved on to the final stage, despite the fact that they are still have trouble cooperating, not only for the prizes, but also for Hayate in a love triangle.
The final stage is about to begin as they are down with the three finalists: the pair of Nagi and Ayumu, the pair of Aika and Chiharu, and the pair of Hinagiku and Miki. Back to the crowd, Izumi and Risa are cheering for Hinagiku and Miki. Then, when Hayate raised a big flag to cheer for Nagi and Ayumu, the crowd tells him to go "down in front", ironically. The final stage is called the "Don't Slip! Press the Button Quiz". Each pair must press the button in order to answer the question, and if the answer is correct, the slides for the other pairs will go up until they slide down to the colored balls. The last pair hanging on the slides wins the tournament. Miki knows that she and Hinagiku will win easily, although she also knows that Hinagiku still have her fear of heights. The final stage has begun, and Hinagiku just answered the first question already. Then, she answered the other questions easily, even without Miki's help. Aika and Chiharu have reached their limit as they slide down to the colored balls, and then they were eliminated. Nagi and Ayumu are in their tight spot as they tried to answer the next question, but Hinagiku and Miki have their upper hand. Ayumu reached her limit, but when she kept hearing Nagi talking about winning a trophy, she finds out that the person in the trophy looks exactly like Hayate. All hope was lost for Nagi as she slides down; however, Ayumu grabbed hold of her, thus saving her. And with that, Nagi and Ayumu finally cooperated with each other. For the next question, Ayumu answered the question correctly as the slide for Hinagiku and Miki rises. The more correct answers Nagi and Ayumu responds, the faster Hinagiku's and Miki's slide rises. They are down with the final question, which is about the cost of the cream puffs. Nagi and Ayumu remembered it when they are in Ayumu's apartment eating cream puffs, and when they answered the question, in which the cream puffs cost 200 yen a puff, the answer was correct. Hinagiku reached her limit as she gets dizzy from the height. Both Hinagiku and Miki gave up as they slide down to the colored balls. They argued during the tournament, but in the end, Nagi and Ayumu managed to win the quiz tournament. And thus, the High School Girls Ultra Quiz Tournament has come to an end.
Later that day, Ayumu, while holding a coupon that she won, thought about inviting her family to a restaurant, until Hayate appeared and congratulated her for her victory. She thanked him, and he later thanked her, and he hopes that he will help her one day. Nagi appeared behind Hayate as they are about to go home to celebrate, but suddenly, Ayumu invites Nagi, and Hayate to go out and eat together in a restaurant. And then, Nagi accepted Ayumu's invitation to a restaurant, and it was the beginning of their beautiful friendship, that is until they argued about the "shabu shabu", or in this case the thin steaks. Maria appeared and explained to the viewers about the "shabu shabu". Mikiri, who is back to be a narrator, otherwise known as "The Voice of The Heavens", ended this episode by saying a lot of lines, just because he made a cameo of himself.