This article is about the manga shot series Ambassador Atom, for the 1952 manga series featuring Astro Boy, see Astro Boy.

Ambassador Atom ("Kitai ningen" アトム大使), or "Captain Atom", as it is known in other regions, is a 1951 manga series written and illustrated by Osamu Tezuka.[1] It was serialized in Shonen Magazine published by Kobunsha from April 1951 until March 1952.[2] The series is mostly notable for introducing Astro Boy who would later become Tezuka's most famous character.

Plot Summary

Some men pick up a boy off the streets of Tokyo and rope him into participating in their new stage show at the Space Theater. He is to physically fight with a robot (Astro Boy) as part of the entertainment. However just before the match begins the boy cries out that his father is in the audience and runs to him. The men are furious about their show being ruined and send one of their big robots to capture him. But when they take him backstage to tell him off he bursts into tears and says he only came to watch the show with his father. Astro suddenly vouches that he is a different boy and one of the men remembers noticing a kid in the audience who was identical in appearance. They are very embarrassed and apologize to the kid and give him something to eat and a car to send him near to his home.

In the meantime the other boy has gone home with his twin’s dad but the man and his wife are amazed when their “son” starts asking why they aren’t going home to the Japanese ship and even more amazed when their real son turns up on their doorstep the following morning just after the impostor has been sent to school. His mother takes him to his school and confront the other boy to the amazement of Mr. Mustachio and all the other kids. Professor Ochanomizu is called over to examine the boys and when he arrives he shows Mustachio a photo of a flying saucer and another photo of the first one blown up, in which Ochanomizu himself is mysteriously seen through one of the windows. One of the identical boys cries out that that is the Japanese ship he came from and so the mother identifies her real son.

The twin explains in tears that he comes from the mountains and rode to Tokyo in a train looking for some adventure. The other boy speaks kindly to him and they promise to escort him home. So a team comprising the two boys, the father, Ochanomizu, Mustachio and one of the other boys are escorted by a mountain guide and they discover the spaceship. Everybody meets a clone of himself when the ship opens and the duplicate professor explains that they originally came from an exact replica of planet Earth. Their Earth exploded but they all escaped in rockets just in time. In addition to their Japanese ship an American and a French ship have also arrived and landed on their counterpart areas of earth. All three countries promise to welcome the immigrants with open arms.

Unfortunately trouble brews between the pair of Dr. Tenma’s. They both lost their only son named Tobio, but unlike the earth version the space version never built him as a robot. He requests his counterpart to introduce him to Astro at the robot show and when they go earth Tenma becomes infuriatingly jealous of the attention space Tenma gives to Astro. He arranges with the secret police to have his space counterpart arrested on charges of planning to take over earth and Tenma kills him with a dangerous liquid formula that shrinks living creatures down to the size of dust particles leaving only their empty clothing behind. When Astro learns about Tenma’s scheme to exterminate all the space people in this way he rebukes his creator who destroys him in rage with a mag-gun. The secret police begin their cold-blooded mission armed with special guns that squirt the liquid like water pistols, and many space people are wiped out including the counterpart of Ochanomizu.

When Ochanomizu and Mustachio protest to Tenma he has them thrown into jail. In the meantime the surviving space people are outraged and declare war. Their combat ships drop atomic bombs and Ochanomizu and Mustachio are blasted in their cell. They both survive and discover Astro’s body among the wreckage of the building they were imprisoned in. Ochanomizu repairs Astro and sends him as an emissary of peace to the space people’s ship.

Astro proposes terms of peace that half of each of the earth and space people move to a neighbouring planet like Mars or Venus while the rest stay on earth and live happily together. It sounds fair to the space people and Astro leaves his head with them as a token of his promise to try his best to persuade the earth people to agree.

However when he returns to earth initially the secret police all listen to Tenma’s insistence that they must never make any treaties with the space people. They say the only way to save earth is the space people’s destruction. Headless Astro declares that he has no choice but to fight against them because their logic is twisted and evil. He runs amuck, smashes the building and chases after themas they run for it. When Tenma’s men say that maybe their reasoning was indeed wrong and they should reconsider terms of peace Tenma tries to shoot them with the shrinking liquid gun calling them weak, despicable traitors. Realizing the danger they all quickly shoot Tenma first and he turns into dust himself.

Afterwards plans are made for all those who are to leave Earth and before the rocket takes off the leader of the space people gives Astro’s head back to him. All is well thanks to Astro.


Ambassador Atom's cape

Astro Boy

Astro Boy is different in appearance from his normal appearance, his spikes are placed differently and he sometimes wears a cape. The manga was re-published in Astro Boy volume 15, the volume gave Astro the normal Astro Boy hair and boots, but kept everything else about Astro Boy the same, and the volume dissociates itself from the normal Astro Boy timeline.

Doctor Tenma

Professor Ochanomizu






Ambassador Atom proved to be a large success especially with young boys in Japan. The character Astro Boy would become so popular he would spin off into his own manga series in 1952.


  • Ambassador Atom recieved an anime adaptation in the 7th episode of the 1963 Astro Boy series.

Collected Volumes

This story has been collected in the following volumes:




External Links

Captain ATOM at

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