Character Sheet for Seiun Kamen Machineman.
Protagonists
Nick/Ken Takase/Seiun Kamen Machineman
Portrayed by: Osamu Sakuta
A Human Alien from the Ivy Planet who comes to Earth to study humans as part of a report to obtain his doctoral degree. Along the way he assumes the human identity of "Ken Takase" and falls in love with Maki Hayama.
- An Alien Named "Bob": He's an alien from a faraway planet with the incredibly normal-sounding human name "Nick".
- Cool Helmet: His transformation into Machineman gives him a pretty slick helmet that covers the top part of his head.
- Henshin Hero: Transforms into Machineman to do battle against Tentacle and their robots.
- Human Aliens: Despite being an alien, he looks exactly like a human outside his Machineman transformation.
- Smart People Wear Glasses: He's an alien university graduate with a Sociology degree who wears glasses in his human guise.
- Superman Substitute: Him being a Human Alien who comes to Earth and falls in love with a spunky female journalist is a pretty clear tribute to Superman and Lois Lane. He even wears glasses.
Ball Boy
Voiced by: Machiko Soga
A miniature robot shaped like a baseball who accompanies Nick to Earth.
- Robot Buddy: Ken's robot companion and sidekick. It also answers questions submitted through the Fourth-Wall Mail Slot alongside him.
- Shoe Phone: Can fold in so it looks just like any other baseball.
Maki Hayama
Portrayed by: Kiyomi Tsukada
A photographer for the Shukan Hit magazine whom Ken falls in love with not long after coming to Earth.
- Deuteragonist: As Ken's Love Interest and the POV for the secondary plots of most episodes, she acts as the show's secondary protagonist.
- Intrepid Reporter: She's always on the hunt for the next scoop.
- Loves My Alter Ego: Maki is smitten with Machineman after she first sees him save the day, but doesn't think much of Ken. The reason Ken doesn't reveal this right away is because he wants Maki to fall in love with who he is as "Ken" first.
- Practically Different Generations: While Maki is an adult, her younger brother Masaru is just ten years old.
Masaru Hayama
Portrayed by: Kazuhito Ohara
Maki's ten year old brother.
- Dude in Distress: Often finds himself imperiled by Tentacle's schemes.
Tentacle
- Nebulous Evil Organisation: Though they have grander goals in mind, for now they're wholly devoted to making children miserable in any way possiblen.
- Offscreen Villain Dark Matter: Despite being a criminal organization, they're never shown to be involved in any operations that would provide them any revenue at all for them to afford all the gadgets and Killer Robots they use.
Professor K
Portrayed by: Hideyo Amamoto
The Don of Tentacle. He's allergic to the happiness of children and thus seeks to use Tentacle's resources to make them sad.
- Actor Allusion: This isn't the first time that Hideyo Amamoto played a Mad Scientist in a Toku show.
- Child Hater: He hates happy children to the point where he's literally allergic to them.
- Evil Genius: He's a genius when it comes to robotics who, instead of using his knowledge to make an honest living, would much rather put it towards terrorizing children instead.
- Evil Is Petty: Even though Tentacle has the resources to accomplish much grander things, K would rather use them to make children miserable. This annoys his right-hand man to no end.
- The Heavy: The plots to most episodes in the first half are instigated by him coming up with a plot to terrorize children that Maki or Masaru end up getting caught in.
- Laughably Evil: Despite being the villain, he's a source of comedy in most episodes.
- Morally Ambiguous Doctorate: He's a criminal mastermind named Professor K.
- One-Letter Name: Apart from the title "Professor", his name is just K.
- Right-Hand Cat: His pet Mechanical Parrot, who is the only other recurring member of Tentacle besides K and Monsu.
- Villain on Leave: He calls it quits after Iron Man Monsu is destroyed and goes on vacation. He returns near the end of the series.
Iron Man Monsu
Portrayed by: Toku Nishio (voice)
The top enforcer of Tentacle, he has much grander ambitions than K and would much rather Take Over the World than terrorize children. Despite this, he remains loyal to his boss.
- Climax Boss: Fights Machineman in #17 and gives him a tougher fight than the Tentacle robots he fought previously.
- The Dragon: He is Professor K's right-hand man and the strongest robot in Tentacle.
- Dragon-in-Chief: Though he technically serves Professor K, Iron Man Monsu is a much more powerful threat and is played seriously unlike his feeble creator.
- Evil Sounds Deep: He's a menacing robot who speaks with a deep growl.
- Killer Robot: The biggest Killer Robot in Tentacle. The first we see of Monsu is him leveling a building to the ground.
Robot Soldiers
Robots built by Professor K to carry out his nefarious schemes.
- Monster of the Week: For the first half, Machineman has to fight one of them Once an Episode.
- Robot Soldier: It's their name. Despite that, they're actually an aversion since K uses them for petty crimes rather than anything that could be considered a military purpose.
- Something Person: Their naming scheme goes "[Motif] Man."
Octopus
- Monster of the Week: Whereas Tentacle used robots as their henchmen of the week, Octopus usually employs a different criminal each episode during their run as the antagonists.
- The Syndicate: Lady M's goal is to grow Octopus into the most successful crime syndicate in the world.
Lady M
Portrayed by: Chiaki Kojo
The niece of Professor K and leader of the Octopus organization.
- Child Hater: She has the same allergy that K does towards happy children.
- Daddy's Little Villain: Seeks to follow in her uncle's footsteps as The Don of a crime organization.
- One-Letter Name: Like her uncle, apart from her title her name is only a single letter.
- The Queenpin: The female Don of a criminal enterprise.
- Villainous Lineage: She is the niece of Professor K and a criminal mastermind just like him. She even has the same disgust for children that he does.
Tonchinkan
Portrayed by: Usaburo Oshima
Lady M's dimwitted manservant.
- The Dragon: He acts as Lady M's assistant in most of her schemes.
- Number Two for Brains: While his boss comes up with the plans, Tonchinkan is a lumbering dolt who does whatever she says.
