The Dokutake ninja steal a shipment of saltpeter from Shinbei's papa. They plan to use it to create medicine that will make them fly and become super-ninjas! Danzou, who's father was transporting the goods, stows away and is taken to the Dokutake's secret headquarters. When Shinbei informs the school, Yamada-sensei and Doi-sensei rush to help. But Hagumi decide to take matters into their own hands and try to rescue Danzou themselves. Things don't go according to plan, though, and soon they all need to be rescued too. Fortunately Rikichi, Yamada-sensei's cool son, is around to help out! In fact,before long everyone gets into the act! But can Rantarou and his friends stop Happousai before it's too late?
The Ninjutsu Academy students return from summer break to hear that due to one of Komatsuda's mistakes, all their summer homework was mixed up. As a result Kisanta, who received an assignment meant for a sixth year, has gone missing after trying to sneak into Oomagatoki Castle to steal their lord's fundoshi. A group including Shinbei and Kirimaru is sent to rescue him, but since Oomagatoki is at war with Tasogaredoki Castle it might be a difficult mission.
After heading off to a duel with the Tasogaredoki ninja, Moroizumi Sonnamon, Mr. Doi has gone missing. While Yamada and the sixth graders begin searching for Mr. Doi, the Tasogaredoki ninja squad leader, Zado Konnamon, and Sonnamon take the podium in the absence of their homeroom teacher in class 1! Meanwhile, Kirimaru accidentally finds out about the situation Mr. Doi is in. Meanwhile, while the sixth graders are searching for Mr. Doi, Amagi, the cold-hearted strategist of the Dokutake Ninja Squad, suddenly appears in front of them. His face is the spitting image of Mr. Doi.
