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.

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!

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 tells students that they'd better revise for the traditional class photo. Revise for a class picture???? Eizan learns that the 'photo' is in fact a test. As the camera clicks, every student has to vanish. A Ninja's first quality is secrecy, and it's out of the question for them to be 'captured' on film. Nobunaga, unfortunately, is unable to disappear. The entire class joins forces to teach him vanishing techniques in record time. Meanwhile, Daisuke can't resist showing off in front of two young girls, and brags that he can turn into a dragon. Naginata and his gang overhear, and sneeringly announce that they'll be at Shuriken soon, to 'defy the dragon'. Now our heroes have two problems to deal with!

Laura and Sam, two private detectives who seem to have come straight out of a detective novel, want to follow a training course at Shuriken with the aim of improving their skills. They need to be able to arrest a gang of audacious thieves. The Principal lets them convince him with a thick bunch of bank notes that Laura offers him. However, it is out of the question that they be taught any secret ninja techniques, that must, as their name suggests, remain secret! Vlad immediately falls under the charm of the young detective. As for the students, they're captivated by Sam's stories!