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!

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...

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.

Jimmy and Pig are so busy playing a videogame they forget about homework. They make up a story about being attacked to explain the missing assignment...a mysterious masked gang attacked them, stealing Jimmy's satchel with the papers... Marcos jumps to the conclusion that the infamous Three Saints Gang is on his trail, and panics. His fears are compounded with Daisuke's claim that he too was attacked, (just to get Ami's attention). Jimmy and Pig's lie is getting them into deep water, and they don't know how to keep their heads above it all.

Kubo has been so terribly boring lately that no one can listen to his classes. If this continues, the kids will end up a year behind. Our three heroes decide to intervene. They want to find out WHY Kubo is so deadly boring. They follow him, and learn that Kubo not only has a very boring life, but that he mutters the same name in his sleep every night - 'Torofi'. They set off to discover the identity of this mysterious Torofi, travelling back into Kubo's past. They learn about an old feud between Kubo and his sister.

A mysterious demon creates havoc in the school, spreading rubbish throughout the corridors and classrooms. Not only are students terrified by this mystery phantom, but also they get punished by the teachers, who blame them for the mess. Our three heroes try to understand what is going on here, and find out who the demon really is. They are in for a few surprises!

In the perspective of an exchange program with an American school, Shuriken welcomes three students from a... Cheerleading Academy! The only school prepared to take on all the costs for the exchange. At first, our Ninja students aren't too enthralled with the new kids. Cheerleading has nothing to do with Ninjitsu skills! Worse, their program is readjusted to suit the new girls - they study the Arts of the Yugei in other words, the Tea Ceremony, Calligraphy, Traditional Music and Flower Arrangements! A few of the boys are subjugated by the three pretty visitors... which means Ami has to cope with competition! Jimmy has a crush on Torrance, who soon becomes Okuni's friend. In short, life at Shuriken School is turned upside down and Eizan - the only one who stays level-headed- has a lot to cope with.

One night, the Principal comes across a Mysterious Ninja in the school corridors. The Ninja gets away from the Principal, but drops his backpack. The Principal finds all sorts of trophies from Katana School inside. He is just getting over the shock of his discovery when the Mysterious Ninja reappears, snatches the bag away from him and vanishes yet again. The next day, the Principal calls an assembly and asks the guilty student to confess. But no one responds. The Principal now threatens to expel whoever did this as soon as he finds out.

The students are busy cleaning, tidying and polishing the school in preparation for a visit from Shuriken's alumni. While students and staff solemnly wait at the Main Entrance an old man appears, leaning on his cane. This is Aiko, the one and only Alumni member to reply to their invitation. He is overjoyed to see the Cleaning Lady again, his erstwhile sweetheart. The students are astonished too see such a dishevelled Ninja. The Cleaning Lady tells them how Aiko, once a great champion, lost his Ninja spirit.

Great Master Otomo is visiting Shuriken School, and holds a conference about the ancient art of eating rice balls. The class is bored silly and the Principal watches Otomo gulp down one rice ball after the other with suspicion. When Otomo sees that neither class nor teachers are interested, he announces that a Great Philosopher living up in the mountain above the town handed on this precious knowledge, which has enabled the hermit-philosopher to live over 300 years! The students, impressed, clamour to meet him.

The Principal tells the students that an election for class leader will soon take place... no ordinary event, this happening is known as a Ninjalection. In this case, the most ingenious candidate gets the most votes... Thus begins a battle for votes between two candidates - on one side Ami (with Tetsuo and Yota in league as campaign managers), and on the other, Okuni, (supported by Eizan and Jimmy). The Principal keeps an eye on their adventures as the two girls vie with each other for vote. And the winner is... ?

Eizan rescues an adorable little chick from prowling tomcats while out walking with Jimmy and Okuni. Although pets are against Shuriken rules, Eizan decides to keep this one until he's fully recovered. Jimmy isn't happy about this, especially when the chick chooses his brand new shoes for a nest! Soon the entire class is in on the secret, but they all promise not to reveal anything... he's such a cute little bird!

Zumichito tells our three heroes the story of one of his epic adventures. At the time he was a young ninja and a Katana student stole the Jade Dragon from him, a priceless treasure that he was guarding. Just as he'd managed to get the treasure back off the thief - who had taken refuge on a boat on Lake Akayama - a huge monster of a fish attacked them. Zumi had no choice but to abandon the Dragon so as to save his adversary from drowning. Since that day, the treasure has lain at the bottom of the lake.

Kubo is in seventh heaven - Kabuki is getting closer, and for several years now, he has been the director. This year, he's decided to pull the roles out of a hat, and the main role ends up going to Eizan...to his great despair! When it comes to getting up on stage, Eizan falls to pieces, especially knowing half the town will come and watch the show! Rehearsals begin but the play is sabotaged by a mysterious ghost who turns the stage upside down!

This time the school is really falling to ruins. Old worn out material, broken floor boards...everyone is complaining to the Principal who finds himself having to search the internet for the cheapest solution to put things right - a kind of home automated computer called Alice...

As Eizan, Jimmy and Okuni are wandering through the shopping mall, a woman has her bag snatched. Our heroes chase after the thief, and, with Ami's help - who was in the middle of doing her shopping - they stop him in his tracks in a most spectacular way. When they take the bag back to the owner, Ami recognizes that it's the famous TV presenter from "Whiz Kids". The presenter is so impressed with their skills that she wants to film them at Shuriken to elect her "young genius" of martial arts for her next show!

Zumichito has invented a revolutionary smoke machine - the Holosmoke. The Principal sees it as a new source of revenue for the school. When night falls, the Principal and Zumichito discover two undercover ninjas in the school and chase after them. The next morning the Holosmoke test run turns into a fiasco. The hologram image of a terrifying monster appears in Zumichito's place, creating wide spread panic amongst the students. Who could have sabotaged the Holosmoke? And who could have placed a love poem on Okuni's chair? Mystery... mystery...

To increase the school's income, the Principal has accepted to house three young stars from the music industry in need of calm and tranquillity. The atmosphere at Shuriken is morose. The stars snub their hosts, their manager is unbearable, and the gym is out of bounds for the budding ninjas. Outside, fans, photographers and TV production vans have flocked in, as if by miracle. Shuriken resembles a besieged fort. The Principal announces to Eizan, Okuni and Jimmy that they are about to carry out their first true ninja mission...

Winter has covered Shuriken with its coat of snow and fog. Visibility is down to a bare minimum and the fog lends a scary appearance to the smallest of bushes. How will the students be able to take their important end of term practical exams in weather like this? The Principal moans, but Kita, as she's flipping through one of Eizan's books, has an idea... The next day, without knowing how they got there, the students wake up to find themselves aboard the "Black Dragon", a vessel on course for... the domain of the Master of Terrible Darkness!

When all the kids start acting crazy in their sleep, it threatens to get everyone expelled from Shuriken School. It's as if all the inner demons of each student are being released in their sleep. Eizan, Okuni and Jimmy must get to the bottom of this mystery ... all they have to do is not fall asleep ... stay away ... stay ... awake ... snoring. Too late!

Something's gone terribly wrong with Eizan's father's rice ball business. All the costumers are complaining about the rice balls. They taste like dirt. It's awful. Business is falling off in landslide proportion. And Eizan soon discovers that the only thing worse than all those rice balls is no rice balls! With the rice ball business going bankrupt, Eizan's family is going to have to move and go back to the family farm on a distant island ... which means Eizan will have to move with them! Which means no more Shuriken School for Eizan!!!