These are other superheroes that exist in Captain-Japan's universe who help him from time to time to battle against SHADOW's forces.
- Furkaizer-01: Jonichi (aka Furkaizer-01) is a 12 year-old squirrel-kid who becomes a superhero armed with a energy-sword.
- Cosmo-Rabbit: an inter-dimensional police-officer who always wears his rabbit-based suit because he can't breath the air of our universe. He is a caring person wth a strong sense of justice and protects the innocent from villains. He is armed with a short sword that also works as a gun called the Cosmo-Edge Blade and a larger carrot-like sword called the Carrot-Caliber. He sometimes teams up with other heroes like Captain-Japan for example to battle common foes, like SHADOW.
- Captain-Japan G: Jamika Miyamoto is cheerful, fun-loving girl who becomes the superhero, Captain-Japan G (Girl). Jamika is really the female version of Jamiko Miyamoto from another universe. After an adventure with Jamiko once, she got stuck in our universe, so she'd stick around for awhile until she can find a way back home. I've based Jamika's battle suit design around a kitten and instead of a sword, she can use cat-like claws to slice opponents in a fight. In our universe, she has become very close to Jamiko=^w^=
- Ai Miyamoto: A 6 year old girl from the stone-age but was frozen for 1000's of years. She was brought back to life in the future by Jamiko & friends. S.P.D has proven through a DNA test that Ai is a ancestor of Jamiko, so she now lives with him and his friends as she tries to learn about this new world. She can speak but she tends to uses both her stone-age words and modern words at once. Her main weapon is a makeshift dagger made of stone and bone, she maybe small but she's quick and she can simply bite her opponents, but she's not very strong. She's is normally playful and friendly for a cavegirl.
- Mekaizer-V1: A highly advanced robotic superhero that petrols Neo-Tokyo alongside Jamiko and other superheroes. He is calm and collected during a crisis and has an A.I based on the virtues of heroes. His main weapon is the Meka-Lance that can use a plasma-shield, laser-blade among other weapons.
- SuperSaurus Rex: Rex was a Tyrannosaurus Rex that was frozen in ice, until scientists from S.P.D defrosted him, but the radiation from the tech used to wake him gave him super powers like flight, heat-vision, freeze-breath and super-strength, it also gave him the ability to speak. So he decided to put on a leopard-print cloth on as a cape and became the hero SuperSaurus-Rex and is one of Captain-Japan's many hero allies in the fight against evil.
- Goliath-Girl: May Tainochi is a normal 12 year old girl, who happens to be the daughter of Dr. Tainochi, a famous scientist and an old friend of Jamiko's dad who made her a special high-tech collar that would allow May to increase her size at will, becoming the superhero Goliath-Girl. In her giant-mode, May has superhuman-strength and relaxes in battle and is always willing to help her friends whenever she is needed.
- Dark-Riders 3: The Dark-Riders 3 are a group of alien/demon hybrids who came together to battle against SHADOW and other such villains because they were experimented on by them to become living bio-weapons. However, they broke free of SHADOW and became heroes in their own right. Using their Devil-Driver belts to access special-powers during battle as well their Fang-Rapier swords. Zaiku Chika is the good-hearted and charismatic leader of the team, Aku Shikumaki is the laid-back but loyal ladies-man and Gazu Tomaku is the team's muscle but is also a gentle-giant.