Along its more than twenty years of airing, its cast has turned so enormous.
This page will describe the more featured characters.
Voiced by: Minami TakayamaThe protagonist of the series. Born into a low-ranked ninja family, he currently attends Ninjutsu Gakuen in order to become an Elite Ninja. While responsible and dedicated, he often goofs around or gets dragged by his friends' antics and gets into trouble along them. He is part of the Health Commitee and has inherited their bad luck strike as well. A good runner with swift feet and a talented artist to boot.
- Affectionate Nickname: While not as often as the other way. Kirimaru calls him Ran-chan.
- Blind Without 'Em: Played straight in the manga, where it's stated that he suffers from horrible astigmatism. The anime greatly tones that down, as his eyesight changes from poor to almost normal according the episode.
- Boke and Tsukkomi Routine: Has one with Kirimaru, notable because they can exchange roles. Both are the Boke to Doi-sensei's Tsukkomi. Referenced in the last episode of the first season.
- Combat Medic: He's training to be both a ninja and a healer.
- Determinator: Even his favorite word is 'Effort'.
- Fiery Redhead: Not helped by his manga incarnation.
- Fragile Speedster: Very fast, 100 mtrs. in 10 seconds, not so durable.
- Hair-Trigger Temper: Has a short fuse in the manga and earlier seasons.
- Image Song: Nintama no Uta and Nintama Go Go Rakudai Song. Both with Kirimaru.
- Meaningful Name: His name comes from the japanese word for astigmatism, Ranshi.
- Pungeon Master: Very prone to this.
- Red Is Heroic: Has auburn hair and is the main character.
- Sequential Artist: His hobbie is drawing pictures of everything that surrounds him.
- Wholesome Crossdresser: He actually looks rather cute.
Voiced by: Mayumi TanakaThe coprotagonist and Rantarou's best friend. He is an orphan, lost his parents during a war. Attends Ninjutsu Gakuen but most of the time he prefers to focus on his many part-time jobs. Miser and greedy, he doesn't do anything for nothing, and always is thinking of ways to earn money. He is often searching for dropped coins and goes into a rush if he sees or senses one. Part of the Library Commitee.
- Attention Deficit... Ooh, Shiny!: Will drop anything he'd would be doing at the moment if he catches the glimpse or shine of a dropped coin or something similar.
- Adaptation Dye-Job: Has black hair in the manga and first episodes of the anime, then it becomes indigo.
- Affectionate Nickname: Rantarou often calls him Kiri-chan. At first, it was out of exasperation, later fully became this.
- Boke and Tsukkomi Routine: Has one with Rantarou, he even used the classic paper fan. Both are the Boke to Doi-sensei's Tsukkomi. Referenced in the last episode of the first season.
- Conveniently an Orphan
- Cute Little Fangs: Has two of them, almost always appear during his money rushes, but he can also use them for attacking.
- Fatal Flaw: His greed can be used by the enemies against his friends and allies.
- Icy Blue Eyes: When drawn in a more realistic style, his eyes are cerulean, contrast with his aloofness.
- Image Song: Nintama no Uta and Nintama Go Go Rakudai Song. Both with Rantarou.
- Money Fetish: He likes to collect and count money.
- New Job as the Plot Demands: Has many jobs and often the plot kicks off when he's performing.
- Only in It for the Money: He'd do anything for a single coin, even things he stated that he won't do.
- Parental Abandonment: His parents died in a war long ago.
- Pungeon Master: Likes adding them to his speech.
- The Scrooge: He suffers, even cries, at the thought of spending/wasting money.
- Wholesome Crossdresser: Does this to perform certain jobs, his skills are outstanding.
- Wingding Eyes: His turns into coins, whenever money is mentioned or referenced.
Voiced by: Teiyu Ichiryuusai
Voiced by: Mami Matsui (S1-S11); Saori Higashi (S12-current)
Voiced by: Chie Sato
Voiced by: Hiroko EmoriHis family runs a carriage service using horses, making him an excellent rider, he shows an especial connection to said animals. Wears in a horse-strolling style, sleeves rolled up and without hakama. Rough, manly and with a very reliable disposition. Often gets into trouble while working in his family business. Part of the Accounting Committee.
- Adaptational Dye Job: His hair is black in the manga. Purple in the anime.
- Animal Motifs: Horses.
- Born in the Saddle: His family uses horses in their business. He's been trained to ride from a very young age.
- Determinator: He works real hard to improve his messy handwriting.
- Doppelganger: He looks a bit similar to Kirimaru.
- I Want to Be a Real Man: A goal of his. In the manga.
- The Illegible: His caligraphy is downright terrible. Has brought headaches to all who tried to descipher it.
- Intergenerational Friendship: Him and Seihachi, his father's employee.
- Interspecies Friendship: He and his family's horses.
- The Leader: He plays this role, whenever Shouzaemon is absent.
- Meaningful Name: Named after a famed ninja master.
- Moody Mount: His horse, surely, has a temper.
- The Reliable One
- Swapped Roles: Their similar looks allowed him and Kirimaru to perform this.
Voiced by: Akiko MutaComes from a martial arts family, He joined Ninjutsu Gakuen to develop more intuition. Loves developing contraptions and setting traps, has an entire room filled with them under his bedroom, which is also full of them. Mischievous and stubborn, a bit cynical. Wants to become a teacher in Ninjutsu Gakuen. Belongs to the Etiquette Committee.
- Booby Trap: Loves those and has set lots in his bedroom.
- Brutal Honesty: Can be a little too frank.
- Bungling Inventor: Some of his devices are prone to malfunction.
- The Cynic: Tends to point out the flaws of almost everything.
- Hoist by His Own Petard: When he forgets when his traps are set. This happens
- Gadgeteer Genius: He's excellent at both devoloping and repairing contraptions.
- Height Angst: He's the tallest in his class. Sometimes it gives him trouble.
- Meaningful Name: Named after Mochizuki Heidayuu from the legendary Koga Ninja School.
- The Trickster: Sometimes he uses his traps to be this.
Voiced by: Hiroko Emori
Voiced by: Kumiko WatanabeBorn into a samurai family, he enrolls late in Ninjutsu Gakuen following his father's advice. He is training to become a first-class swordsman, often obsessed over his training routine despite having notable skills. Straightforward and honest with a firm voice, can be very literal-minded sometimes. Part of the Physical Education Committee.
- Adaptation Dye-Job: In the manga, his bangs were blonde. The anime turned them brownish.
- Disappeared Dad: Played with. His father faked his death in order to allow him become stronger.
- Heroic RRoD: Is prone to this when he overdoes his training.
- Kid Samurai: Comes from a samurai family.
- The Klutz: In his debut episode. He had cornered the whole class and their teacher in the furo, ready to strike with his sword, then he steps on a soap bar and gets knocked out after slipping and clashing with a wall.
- Literal-Minded: Not so often, but has his moments.
- Meaningful Name: He's named after Minamoto no Yoriie's posthumous name.
- Odd Friendship: With Ibuki, from the Dokutama.
- Only Sane Man: Tries to play this role among his committee's members.
- Samurai in Ninja Town: Due to his heritage and studying in a Ninja Academy.
- Weapon of Choice: A bokken. In his debut he had a real katana.
- You Killed My Father: His debut episode revolves about him searching for his father's murderer.
Voiced by: Tomiko Suzuki (S1-S11); Saori Sugimoto (S12-current)
Voiced by: Yuko Kobayashi
Voiced by: Yuko Sato
Voiced by: Kikumi Umeda
Voiced by: Mitsuki Saiga
Voiced by: Komatsuna Sakato
Voiced by: Mayumi Oota (S11); Touko Aoyama (S12-S16); Komatsuna Sakato (S16-current)
Voiced by: Kumiko Watanabe (S10-S16); Sayuri Yoshida (S16-current)
Voiced by: Junko Shimakata
Voiced by: Chie Sato
Voiced by: Urara Takano (S1-S6); Fuuko Shinomiya (S6-current)A Second Year from I-Class. Born into a fishermen family, making him excellent at swimming and water combat techniques. Likes to tease and prank the First Years, often going so far, which has made them to dislike and consider him the worst senpai. Despite that he can be kind and supportive to them, sometimes. Part of the Explosives Commitee.
- Adaptation Dye-Job: Has brown hair in the manga, olive in the anime.
- Brutal Honesty: He often speaks without filter and says too much.
- The Gadfly: His pranks are often found funny, by others than the victim.
- Good Is Not Nice: Sometimes he tries to be a good senpai and help his juniors, not without picking on them.
- Hair-Trigger Temper: He loses his cool quickly when ignored.
- I Just Want to Be Loved: Gaining his juniors appreciation is a main goal of his.
- Innocently Insensitive: A few times he doesn't realize that he's hurting others.
- It Amused Me: Most of his pranks are for his own fun.
- Jerk with a Heart of Gold: Despite his pranks towards the main trio. He's fond of them.
- Nice Guy: Strangely when he's not pulling pranks on the first years, he's this.
- Practical Jokes: Has many in his arsenal.
- The Prankster: It's the resident one in this campus.
- Troll: What his victims think he is.
- Troubled, but Cute: He often hides his worries about his juniors disliking him beneath his trolling attitude.
- We Want Our Jerk Back: The main trio prefer him teasing them than being downright nice.
- When He Smiles: He claims not knowing how to smile and sometimes tries to practise how to fake one, looking weird in the process. But when it comes naturally, it makes him look adorable and others like him better.
- Yellow Eyes of Sneakiness: When drawn in a more realistic style, his eyes are shown to be golden. Adding his pranking tendencies.
Voiced by: Atsuko Mine (S1); Ai Sato (S2-S8); Jin Domon (S8-current)
- Early Installment Character Design Difference: In earlier seasons, his face is slightly different.
Voiced by: Yasuhiro Takato (S3,5,6,12); Urarako Suzuki (S9,13); Yukiko Amada (S16-current)
Voiced by: Kokoro Kikuchi
Voiced by: Hiro Yuki (S1-S3); Isshin Chiba (S3-current)
- Animal Motifs: Snakes
Voiced by: Kouki Miyata
- No Sense of Direction: He gets lost very easily.
Voiced by: Touko Aoyama
Voiced by: Mari Maruta
- No Sense of Direction: Same reason as Samon.
Voiced by: Sumomo Momomori
Voiced by: Hiro Shimono
Voiced by: Wataru Takagi
Voiced by: Shinobu Adachi
Voiced by: Akira Ishida
Voiced by: Daisuke Namikawa
Voiced by: Yuuki Kaji
Voiced by: Junichi Kanemaru
Voiced by: Takumi Yamazaki
- Master of Disguise: To the point that nobody can see his real face.
Voiced by: Toshimitsu Oda
- Trademark Favorite Food: Tofu
Voiced by: Ryuichi Azuma
Voiced by: Shigeru Shibuya
Voiced by: Ken Narita
Voiced by: Soichiro Hoshi
Voiced by: Shigeru Shibuya
Voiced by: Nobutoshi Canna
- Catchphrase: IKE IKE DON DON!