When Kenichi watches TV, Ninja Hattori enters and surprises Kenichi. Hattori does all the household work and surprises Kenichi and his family.

Koike-Sensei gets afraid of Hattori's shadow and runs to school. He scolds Kenichi at school, but Hattori saves Kenichi.

Kenichi wants a model locomotive. He tries to save money by helping out at home, but Hattori finishes his errands before Kenichi. Hattori-kun is kicked out by Kenichi who gets angry, but he starts a part-time job at a soba restaurant for Kenichi.

Shishimaru (Ninja dog) helps Kenichi and Yumeko from a dog and disappears. So, Hattori catches Shishimaru and brings him home.

Hattori makes Kenichi study hard and does not allow him to rest. As Kenichi scores good marks, Ama gifts them both.

Kenichi takes Hattori's help and does all the household work. Kenichi surprises his parents on their wedding anniversary with a celebration.

Hattori trains Kenichi to play baseball. But as Kenichi fears to play the match, Hattori plays on his behalf. Later, Kennichi plays and wins the match.

Amara meets Hattori and fights with him. So, Hattori decides to teach Amara a lesson, but Koike-Sensei scolds Kenichi.

Shinzou finds Hattori and helps him get rid of Amara. Hattori introduces Shinzou to Kenichi's family.

Koike-Sensei visits Kenichi's house. Shishimaru loses his grip and falls on Koike-Sensei and gets him unconscious.

Shinzou loses his way and the list. So, Shishimaru and Hattori guide him. Shinzou tells everyone about his deed.

Yamamoto visits Kentaru as a schoolmate. In the night, Yamamoto robs and tries to leave but gets caught. A cop declares a reward to the family.

Kenichi takes Hattori and Shinzou's help and wins the race on sports day.

Hattori and Kenichi click pictures of Kemumaki's cat while he robs the fruits and proves Kenichi innocent to the neighbour.

Kenichi gets a bad dream of Kemumaki threatening him and gets afraid to go to school. On seeing the doctor, Kenichi reveals the truth and makes Kemumaki his friend.

Kenichi impresses with his picture of a UFO. After returning home, Hattori tells Kenichi the truth about the UFO.

Kenichi insists Hattori on teaching him the Ninja technique and misuses it. Kenichi promises Hattori to use the technique at the right time.

Kenichi enjoys his day and forgets to complete his homework. Next morning, he is surprised to see his homework completed by Hattori.

Kenichi assumes Shinzou has been kidnapped. After a lot of struggle, Hattori and Kenichi are shocked to find Shinzou with Koike-Sensei.

Kenichi takes training from Shishimaru and acts just as Shishimaru teaches him. The audience has a hearty laugh watching the talent show.

Kenichi and his friends visit the cocoa garden. While plucking the fruits, they get caught by the manager, but he allows them to take fruits.

On hearing Shinzou's cry, Hattori shows the family a room that he uses to meditate at night.

The Mitsuba family visit the zoo. Shishimaru shows his ninja techniques to the lions as he wishes to be like them.

Kaiko Sir announces students to sketch in autumn. Hattori takes a goat's look and eats Kemumaki and Kenichi's drawing paper and saves them from feeling ashamed before the teacher.

The school takes the students for a picnic. Kemumaki provokes Hattori to fight but Hattori stays calm on Kenichi's insistence.

Kenichi and Kemumaki shows Yumeko movie ticket. They fight for going with them. Then Yumeko goes with Shinzou.

Kenichi sees Yumeko posting card in Letter Box with praying for doll. So Kenichi helps Yumeko for Doll. Kenichi wins a doll prize. He gives to Yumeko.

Kenichi finds fishing rod in cupboard but it broke. So, Hattori makes New fishing Rod. Kio gives garbages to Hattori's fishing rod with avoiding fishes. Shinzo brings big fish from market.

Kemumaki finds eraser in ground so he shows to Kaiko Sir so he gives Kenichi incharge to find lost properties. So Shishimaru smells and find every lost property.

Kemumaki troubles Kenichi and calls Hattori Kenichi's bodyguard. On seeing Kemumaki treat a dog with care, Kenichi, Hattori, and Shinzou are shocked.

Misuba checks flower not grown. Then Kenichi's father brings box of sweet potatoes. Then Kenichi and Shinzou gets trouble of potato. Then they dig ground and hides potatoes then Hattori grows flower full of potato.

Kenichi forgets his book at home. So, Hattori and Shinzou go to Kenichi's school. But Shinzou's cry makes everyone faint.

When Papa sits in train so Misuba tells that He has become fat. So He starts dieting by not eating food. He sees everything as Food.

Kenichi and his friends reach Tokyo without informing their parents. After returning, Kenichi's parents have a discussion about the trip.

Shishimaru and Kenichi find a gold coin, but Shinzou loses it. Later, Hattori returns the gold coin to Kenichi's parents.

Hattori hypnotises Kentaru to find the person who has robbed Kentaru's salary. He catches the thief and returns Kentaru's money.

Kenichi uses magic tricks on his teacher. Later, Kemumaki uses magical tricks on Kenichi and makes him his pet.

Kenichi plays dodgeball with their friends. Hattori teaches Him to play dodgeball. So Hattori makes him dodge ball. To teach him lesson. Then He turns into lion.

Kenichi's Neighbour gives a Yuki baby which trouble. This Baby troubles Kenichi and Hattori. Then Kenichi's Neighbour then takes Yuki back.