CARTOON CHARACTER

• Kanzo Hattori (ハットリ カンゾウ or 服部 貫蔵 Hattori Kanzou) (voice: Junko Hori, drama actor: Kōtoku Nomura, drama voice: Kazuo Imakura, live-action film actor: Shingo Katori), aka Hattori-kun, is the protagonist of the series, a little ninja. He is 11 years old and 40 kg and is 140 cm tall. He is the boy who usually contests Kemumaki when he performs pranks. Hattori's main weakness is that he is afraid of frogs; this often leads him into trouble. He wears blue coloured ninja robes. He is also afraid of lizards. He always explains what a good ninja does and likes meddling in his friends' business.
• Shinzo Hattori (ハットリ シンゾウ or 服部 心蔵 Hattori Shinzou) (voice: Yūko Mita, drama actor: Shigeki Nakajō), aka Shin-chan, is Kanzo's younger brother. A good point to note is that while Kanzo is referred to as "Hattori", Shinzo is usually called by his regular name. He uses weapons made from wood. He is a ninja-in-training who learns to be a good ninja, like Kanzo. He wears red coloured ninja robes. Shinzo seems to have a good heart and sticks being loyal to his brother and sometimes gets excited when others are excited. Some of the times, Shinzo tricks Hattori to giving him things.
• Shishimaru (獅子丸) (voiced by Kenichi Ogata) is a ninja dog living with Ken'ichi, who came along with Kanzo Hattori and Shinzo Hattori. He is the light-headed dog who, along with Shinzo, winds up doing pranky things. His fur color is yellow.
• Ken'ichi Mitsuba (三葉 ケン一 Mitsuba Kenichi) (voice: Masako Sugaya, drama actor: Katsumi Takamiya, live-action film actor: Yuri Chinen) is a regular boy who goes to elementary school and does poor with his studies. He dates Yumeko, however Kemumaki is always after her.
• Tsubame (ツバメ) (voice: Fuyumi Shiraishi) (called Sonam in the Indian version), aka Tsubame-ko, a kunoichi and classmate of Hattori-kun. She loves Hattori and always wishes to marry him. She has a dislike for Ken'ichi, Shinzo, Shishimaru, Kemumaki and Kagekiyo. She wears pink coloured ninja robes. Tsubame seems to own a recorder, a clarinet, a flute, a piccolo and a bassoon, five woodwind instruments.
• Kemuzou Kemumaki (ケムマキ・ケムゾウ Kemumaki Kemuzou) (voice: Kaneta Kimotsuki, live-action film actor: Gorie) is the antagonist of Ninja Hattori-kun. He, along with his cat Kagechiyo Kemuzou, always are the ones who cause trouble. He competes with Ken'ichi for Yumiko-chen; however when he uses one of his ninja techniques in order to win, Kanzo usually steps in to save the day. He wears green colored ninja robes. 
• Kagechiyo (影千代) (voice: Eiko Yamada) is an animal-ninja of the Koga-  ryu, Kagechiyo is the helping antagonist of Ninja Hattori. Usually Kemumaki gives a big task in his plans for Kagechiyo to carry out, but he foils it. He is seen to have an enmity of Shishimaru. His fur color is black.
• Yumeko Kawai (河合 夢子 Kawai Yumeko) (voice: Runa Akiyama), aka Yumeko-chan, is the girl who usually causes disputes between Kemumaki Kemuzou and Ken'ichi Misoba. She is a girl who attends the same elementary school as the two, and she is also the one who causes most of the problems of the plot. Yumeko seems to be in touch with Hattori some of the times. Yumeko sees Hattori as a big brother and Shinzo as a little brother. She is also seen to like kenichi. And sometimes people mistake her relashionship with hattori as a romantic one. though, in some episodes they are seen to show romance.

Other characters include:  

 

• Aiko-sensei (voice: Yōko Kawanami) : Ken'ichi's music teacher. Koike-sensei has a crush on her.
• Hattori Jinzou (voice: Tadao Futami), Hattori-kun and Shin-chan's father.
• Jippou (voice: Junpei Takiguchi, drama voice: Hiroko Maruyama): a giant turtle monster ninja.
• Koike-sensei (voice: Issei Futamata): Ken'ichi's teacher, also appears as a ramen chef in Obake no Q-tarō and Doraemon. He always scolds Kenichi similar to when Nobita is scolded by his teacher in Doraemon.
• Kentarou Mitsuba (voice: Yuzuru Fujimoto, drama actor: Teizō Muta): Kenichi's Pop. He usually smokes and comes from his office late in the evening. He likes golf a lot.
• Kenichi's Mother (voice: Yuri Nishiwa, drama actor: Chiharu Kuri): The mother of Kenichi. She likes Tsubame and thinks that Kemumaki is a good boy.
• Professor Shinobino (voice: Reizō Nomoto): A professor who lives in America and invented Togejirou.
• Robomaru (voice: Banjō Ginga):
• Shinobino O-hime (voice: Keiko Yokozawa)
• Togejirou (voice: Hiroko Maruyama)(called Cacto-chan in the Indian version): A cactus having supernatural powers is sent by Professor Shinobino from America. He is competition for Shishimaru.