The episode starts off with Naruto and Chouji wanting some ramen. When they get to the Ichiraku Ramen shop, they notice that its closed. As they start to walk away, Chouji smells ramen cooking so they crawl into the ceiling through the vent. Once inside, they see Mr. Ichiraku cooking feverishly. After he discovers them in the ceiling, he offers him the new ramen dish he's been trying to perfect. Shortly after Chouji insults the quality of the noodles, Mr. Ichiraku collapses from exhaustion.
The episode continues back at Mr. Ichiraku's place where Sakura is treating the massive burns on his fore arms caused by the non-stop cooking he had been doing. Mr. Ichiraku tells Naruto, Chouji, and Sakura about the Ryourinin (Cooking Ninja) led by Hakkaku who kidnapped his daughter and the terms of her return: Mr. Ichiraku hands over his Legendary Ramen recipe or win a cooking contest. All three offer to help him, and since Mr. Ichiraku has no idea what the "Legendary Ramen recipe" is, he spends the rest of the night teaching the three the basics of ramen making in hopes of winning the contest.
The next day is the cooking contest and after several mishaps, the three are down to their last set of ingredients. Naruto gets the idea that in order to make great ninja ramen, they should use ninja skills to make the noodles. After Naruto uses the Rasengan to mix the ingredients, he shapes the dough to resemble Ero-Sennin which irritates Sakura. After she proceeds to thoroughly pound the dough, Naruto tosses the dough to Chouji who uses his Partial MultiTechnique (Both Arms) in order to properly stretch the noodles.
Hakkaku realizes that Mr. Ichiraku is going to win the contest so he frantically reminds Mr. Ichiraku of a big rule: You must serve the judges in the order they arrived. Since there were around 100 judges, Hakkaku feels good about his chances to win until Naruto smiles and uses his Kage Bunshin No Jutsu and proceeds to serve all 100 judges at the same time. After admitting defeat, Hakkaku allows Ayame, Mr. Ichiraku's daughter, to return to her dad. Everyone is surprised when an over young lady comes running out.
Hakkaku and the Ryourinin then apologize to Mr. Ichiraku and proceed to tell him the reasons behind their kidnapping. Apparently, the ryourinin were being phased out because they were cooking meals that would not only fill a ninja's appetite, but also makes them gain weight which leads to the degradation of their speed and quickness. After thinking for a few minutes, Mr. Ichiraku comes to the realization that he did have the Legendary Ramen recipe all along, but the true name of it had been misinterpreted over the years. He gladly gives them the recipe so that they can continue to be useful.
Back in Konoha, Mr. Ichiraku had just finished creating a Diet Ramen to slim down his daughter and all the females in town love it. When Naruto and Chouji go to see Mr. Ichiraku, they find an extremely skinny man. They come to find out that Mr. Ichiraku ate the Diet Ramen with his daughter, thus explaining his skinny new appearance.