Eizan has to help his dad make rice balls for the Tokirohama Bonanza Weekend and he's so tired he fails his school exercises. To motivate him, Okuni secretly signs him up for the Martial Arts Festival Competition, scheduled to close the Fair. The organizer is no other than the leading Ninja Equipment supplier for all schools - Mister No. He bumps into Kita at the mall, one of his old classmates. He sneers at her because her career has lead her to teach in the most 'rundown Ninja school in town'. Stung to the quick, Kita answers back by betting that Shuriken will win his competition. Mr.No accepts the bet, but If Shuriken loses, he wants all the school's overdue payments to be settled at once. In other words, Shuriken's survival is in Eizan's hands...

Bakufu, the famous Ninja master, literally drops out of sky (hence the hole in the school's roof) and offers to teach at Shuriken School. The Principal doesn't dare refuse, but Bakufu's fee is exorbitant. While the Principal attempts to come up with moneymaking schemes, a mysterious thief starts stealing things from the students! Eizan, Jimmy and Okuni investigate. Their prime suspect is Bakufu, because these incidents surprisingly coincide with his appearance at the school ...

The Principal is happy. A wealthy man is considering placing his son, Kazumi, in Shuriken School, along with a huge cheque, which would put an end to the school's financial dilemma. But first, the boy will spend a day at the School, to see if he likes it. Kazumi seems to appreciate Eizan, so the Principal puts him in charge of looking after the boy. But Kazumi is so spoiled rotten, that soon everyone avoids them (even Eizan's friends avoid him). The teachers themselves threaten to resign. Eizan feels miserable. When the Katana kids jump in and kidnap the boy, Eizan is faced with a choice. What if they just keep him? Well...perhaps not.

Eizan, Jimmy and Okuni see a mysterious Ninja tell Vlad that he's failed Evasion Techniques for Experienced Ninjas, final Exam for the correspondence course he's been following. When still a student, Vlad didn't have time to finish his exams, and the truth is he doesn't have the required teaching diploma. To his despair, all he can do now is resign! No way will Eizan and his friends let their favourite teacher quit! Kubo's subject right now happens to be 'escape tactics'... Vlad can take the course, pass the exam, and he'll be qualified to teach! But how can they help Vlad take Kubo's class without everyone finding out his secret? With their typical 'ninja-magination' and... a good shave!

As the School prepares to celebrate the anniversary of the town's foundation, a mysterious Ninja from Katana School makes off with Tokiro's (the city's father) famous flip-flops. According to tradition, Shuriken presents these flip-flops to the public during the commemorative parade. If Shuriken School cannot produce them, the school's entire assets will be handed over to Katana School!

Jacques cheats to get the better of Okuni in an exercise, with an unfortunate result - Kubo gets lost inside a labyrinth! He was there to prepare the ground for a practical exam scheduled for the Academic Inspector, a grim character with a daunting reputation. While Eizan, Jimmy and Okuni set off in search of Kubo, the rest of the class tries to convince the Inspector and the Principal that Kubo is busy teaching them...