Jamiko Miyamoto: Jamiko Miyamoto is the story's main protagonist, a 10 year old kid who is from a samurai family. Jamiko is a nice, well-meaning kid who has never been in trouble his whole life and get's along very fine with people. However, he is also very shy, timid and gets upset very easily if teased, but those don't stop him from waiting to do the right thing, even standing up to bullies to protect his friends due to his strong sence of justice. When Jamiko was 3, his parents, Ryu & Sakura Miyamoto, were killed when Lord-Destruction sent some of his mutant-warriors to attack the dojo where he lived. Jamiko was placed in the care of Man-Chu and now lives with him and his friends at his old family home, that has been rebuilt with special devices built by Man-Chu to help Jamiko protect Neo-Tokyo as like a secret superhero HQ of sorts.
- Captain-Japan: Captain-Japan is Jamiko's superhero alter-ego. Unlike Jamiko who is timid & shy, CJ is more outgoing, laidback and calm. He's also abit of a wisecracker who like's a good fight. But he also has a strong sence of justice just like Jamiko and is willing to protect the innocent is his is need. Highly skilled in both hand-to-hand & weapon-based combat. His main weapons during combat are his Samuraizer-Sword, his D-Pistol sidearm, and the Cybermaru sword, which he can dual-wield with his Samuraizer.
- Armor-Joe: a S.P.D built support-robot that CJ can summon at will during missions. His main torso transforms into a powerful laser-cannon and his limbs can transform into twin machine-guns.
Main Surpporting cast:Edit
- Man-Chu: Man-Chu is Jamiko's guardian and mentor, he's also the one who created the J.A.P.AN Unit. Long ago, he came to Earth in Japan during it's Edo era, when he learn that SHADOW were about to attack to Earth so he gave the J.A.P.A.N Unit to Jamiko's ancestor Yoritomo Miyamoto and he was able to stop the invasion. Ever since then, Man-Chu has been with the Miyamoto family throughout the years as the family-friend and guardian.
- Lola Tachikawa: Jamiko's main love intrest. She later became his girlfriend. She's a nice girl and one of the few Earthlings who knows Jamiko's superhero alter-ego. She also lives with Jamiko, Man-Chu and Chocolate & Mint at the Miyamoto Dojo/HQ. Lola's father was friends with Jamiko parents and Lola & Jamiko because friends because of that and it was love at first sight for the two.
- Chocolate & Mint: A pair of rabbit/insect aliens who live with Jamiko and the gang. Chocolate is the blue older brother, he's a little joker and often gets in trouble but he's a real softy sometimes. Mint is the pink younger sister, she's more calmer then her brother and is abit of a girly-girl.
- Latifah: A 15 year-old S.P.D trained rookie who was trained in spear-based combat. She came to live with Jamiko & the gang to learn from Man-Chu. She quickly because friends with Jamiko and his friends, and is like a loving big-sister to Jamiko (with him being an only child). She also helps him fight the bad-guys from time-to-time.
- Pokyo-Chan: Pokyo-Chan is Man-Chu's comical robot assistant, based around a toy robot. He helps out Man-Chu around the lab and also helps Jamiko & the gang with their homework. He is very playful, fun-loving but also hard-working as well. He not designed for combat but he does have a stun-gun in his right hand, just in case.
These are Jamiko's classmates/surrporting cast at Neo-Tokyo Junior High-School.
- Dean, Tracy and Ned are the school-bullies.
- Robot Rob is the class nerd.
- Boo is a emo-kid and Joe is Boo's cheerful best friend.
- Timmy-Spike is the school-clown and Alex & Jerry are the school's hearthrobs.
- Mimi, Kitty and Ceratops (aka The Go-Go Girls) are a group of girls who are huge fans of Captain-Japan (without knowing that their classmate Jamiko is their hero).
- Pen Fujiwaka is the school's lead cheerleader and who (like Lola) has a crush on Jamiko, She is also one of the few Earthlings who know Jamiko's secret alter-ego.
- Apple & Lena are Pen's best-friends fellow cheerleaders. Lena's a sweet but tough girl who's not afraid to speak her mind and like J-Rock music. Apple's a fun-loving & kind pony from a humble farm. She likes to host slumber-parties for her friends. She & Lena are also good friends with Jamiko, but don't know that he's Captain-Japan (unlike Penn who does know).
- Garterbelt The principal of Neo-Tokyo Jr. High-School, this guy runs the school like when he was a police-chief back in the 70's. He's also a fan of disco-music.
- Rocko: The friendly school janitor & handy-man.
- Miss Nicoles: Miss Nicoles is a friendly, kind-hearted teacher who everyone loves. She is one of the few adults who know's Jamiko's secret life as a superhero.