First serialized from October 1965 to March 1966 in Shonen magazine.

The Blue Knight is a rebel robot. He was created by Dr. Los who named him Blue Bon but he has abandoned his creator to become a guerrilla fighter against the current robot law. The Blue Knight travels on his flying robot horse armed with his lance attacking places such as mines where robots are installed as workers and reprocessing factories where old robots are turned into scrap. Though Dr. Los begged him not to hurt any humans when he ran away, the Blue Knight feels no remorse if humans are killed in his attacks nor does he hesitate to destroy other robots who oppose him. He sees them as stupid fools sticking up for humans who treat robots as slaves.

Astro is approached by the Blue Knight at his house at night and the Blue Knight actually wants him to unite with him and create a robot kingdom where robots don't have to do anything humans tell them to. Astro protests that he cannot allow innocent humans to be killed and fights with the Blue Knight. Blue Knight escapes but his helmet is cracked. Later in the south of France the Blue Knight fights and destroys a robot called the White Knight built by the French Ministry of Science to oppose his reign of terror against humanity. However his damaged helmet finally breaks off completely and the French Science people are shocked to see what he looks like as he flies away. Astro has been pursuing the Blue Knight and the Frenchmen point in the direction of the sea. Astro dives underwater and catches him just as he is putting a new helmet on. Astro is amazed that the Blue Knight has the face of a young robot boy named Tonto. Tonto had recently joined Astro's classmates and caused some concern when he punched Shibugaki when he was teasing him. Shib had dared Tonto to hit him knowing that the Robot Law forbids robots to hit humans and Shib hit him first in fact. Tonto retaliated and hit Shib back. Astro tried to explain to Tonto that he could have killed Shib irrespective of how mean he was treating Tonto, but Tonto didn't care. The Blue Knight denies his name is Tonto and he and Astro have another duel on the ocean floor.

While they fight the Blue Knight notices an approaching submarine and departs telling Astro they shall settle their differences another time. Humans in diving gear emerge and Astro tells them the Blue Knight was here. One of the men calls himself Count Burg and he has been seeking a fight with the Blue Knight. They realize he was in such a hurry he left his sword behind and Astro gets a shock when he touches it. Count Burg takes the sword back to the Ministry of Science and through conducted tests finds out that some robots can hold the sword fine while others receive a shock. He declares to all the scientists and police that only robots of the same kind as the Blue Knight can hold the sword so therefore they must be dangerous like him. Inspector Tawashi agrees with Count Burg that the sword must be manufactured and duplicated so that the police can get every robot to try holding it. If it gives them a shock they are innocent. Otherwise they are to be sent to the scrapyard to protect the public. Professor Ochanomizu objects to this insane reasoning but he is over-ruled. Thus many helpless robots are dragged off protesting they have done nothing wrong.

Astro and his family are certainly not exempt from this test. Even though the sword “clears” him, Uran and Cobalt, their parents are both deemed dangerous. They try to appeal to Ochanomizu for help but are told the Professor has been away on a trip for the last three days and his location is unknown. Rather than allow his parents to be scrapped Astro rebels against the police and takes his mother and father out of their clutches. He and all his family go to join the Blue Knight in Japan's mountain ranges with hundreds of other fleeing robots. Astro still doesn't want to hurt humans needlessly but he supports building a new robot nation after all the unjust things humans have recently done. The Blue Knight welcomes Astro and shows him his face. Astro is amazed that he doesn't look like Tonto anymore.

Meanwhile back at the Ministry of Science Count Burg has secretly tied and gagged Professor Ochanomizu in the basement. Everybody thinks he went off and didn't return but the Count has made him a prisoner. When Count burg receives a tip that the Blue Knight is preparing to make a robot nation in the mountains he mobilizes attack forces with tanks and missiles. The robots hold up against the initial onslaught but then they are hit with a huge electromagnetic pulse that paralyzes them. While Astro and the others are helplessly stuck missiles rain down all around them. Cobalt and Uran tunnel underground and capture Count Burg dragging him through the passage to the Blue Knight's camp. The Count is forced to order his men to switch off the magnetic pulse but he commands them still to fight with everything they have. When Astro and the other fighting robots run low on energy all the robot civilians courageously donate their own. Eventually the Count is rescued by a huge flying battleship but never-the-less the Blue Knight gets the upper hand and he is recaptured and his army defeated.

The Blue Knight declares his intention to execute all the human soldiers. When Astro protests he has to fight the Blue Knight when suddenly the Blue Knight's creator Dr. Los appears with Professor Ochanomizu, who he has rescued from the Ministry of Science's basement. Dr. Los is about to explain the truth about the Blue Knight's past when suddenly the Blue Knight throws his spear to kill him. Astro intercepts it to save Dr. Los and is destroyed.

Professor Ochanomizu rebukes the Blue Knight and tells him while he may hate humans some robots are prepared to lay down their lives for them. Just like Astro died to protect Dr. Los. The Blue Knight is humbled and consents to allow his creator to tell Ochanomizu his history.

Dr. Los originally created the Blue Knight as a handsome young robot adult named Blue Bon. Later he built a younger sister and small brother for him. Their names were Maria and Tonto. He loved them all just like his own children. One day the evil Count Burg visited their home to propose to Maria. Even though she was a robot the Count was so taken by her beauty he didn't care. Never before had a human ever taken a robot for a bride but Maria was very happy about it and so Dr. Los and Blue Bon gave their consent.

But the Count showed his true colours when he took Maria to live on his estate. He hated robots though he seemed to initially love Maria. He said she was different from all the robot vermin who were his servants. However as she constantly objected to his cruel whipping of them she began to be abused herself. When the Count caught her in the act of phoning Dr. Los he beat her very badly with an electric whip. Young Tonto took a flying car to rescue his sister but they were caught and the cruel Count smashed both Tonto and Maria to pieces and dumped them on Dr. Los's doorstep. Blue Bon went insane with grief and rage. He attacked Count Burg's castle destroying it. Count Burg was furious at the destruction of his property and vowed to have a showdown.

Ochanomizu can understand why Blue Bon hates humans now but is puzzled about something. Tonto was going to Astro's school and he also spoke with Maria at Tonto's home a good while back. How can this be if they were both destroyed? Dr. Los and Blue Bon both explain the answer. Los couldn't bear the thought of just throwing their bodies away so he modified Blue Bon with the ability to transform sometimes into Tonto and other times into Maria. But he did this without Blue Bon's knowledge and when he found out he began to hate even his own creator. Blue Bon felt like a freak and so Dr. Los built him suit of armour and a helmet to conceal himself. Then he left to pursue his dream of destroying the robot law and building a nation where robots can be free. The Blue Knight removes his armour and demonstrates his shape-changing.

He deeply apologizes for what he did to Astro and hopes that Ochanomizu and Los can repair him. Count Burg seizes his chance and breaks free from his guards. Snatching up Blue Bon's own spear he drives it through his back while he is unprotected by his armour making him explode. He cackles in triumph but Professor Ochanomizu is enraged and delivers a very violent, much deserved comeuppance. He bashes Count Burg in the stomach and face, finally driving him into the ground with his enormous nose just like a hammer and a tent peg.

Astro's family are all devastated but the Professor vows to do everything he can to repair poor Astro.


The Blue Knight is a frequently recurring character in the most recent animated series of Astroboy from the 2000's era. He has very similar goals and attitudes but he has a completely different background story and does not transform into any other robotic forms. Also he has a happier ending and takes his followers into outer space to find another planet where they can build their robot nation in complete peace and freedom.

There is a continuity reference within dialogue shared between Ochanomizu and Mustachio while they are driving to Tonto's home where they speak to Maria regarding the way her little brother hit Shibugaki at school. Ochanomizu reminds Mustachio about the case involving Atlas. Atlas was the first recorded instance of a robot deliberately hurting humans and he had the dreaded Omega Factor built inside him.


First serialized from March to May 1966 in Shonen magazine.

Following on chronologically from where the Blue Knight left off this story deals with Professor Ochanomizu's attempts to repair Astro. Ochanomizu tells the Ministry of Science that ultimately they will need the help of Astro's creator Dr. Tenma to successfully repair him. They broadcast an appeal to Tenma over radio, television and satellite. Finally Tenma contacts Ochanomizu and arranges a secret meeting at the airport late at night.

The Professor keeps the appointment but Tenma demands that if he helps repair Astro, he must be given ownership of him again. He doesn't care about Astro's family. He just wants him back as his son. Ochanomizu says he cannot agree to Tenma's demands and so for the next month the ministry strive to repair him themselves. But after twenty-three failed attempts Ochanomizu admits defeat and calls Tenma. But when Tenma further demands that Astro's robot family be scrapped, the Professor gives it one more try. But yet again he fails

Astro's mum and dad tearfully volunteer to be scrapped for the sake of Astro and promise to explain things to Cobalt and Uran. Ochanomizu is not happy but he lets Tenma come to pick up Astro and take him to his secret laboratory. He does however insist upon accompanying Tenma and Tenma doesn't object for the sake of their old friendship. He shows Ochanomizu all the other large advanced robots he has been building and shocks the Professor by declaring that his son Astro is destined to become the robot who will conquer the world. Tenma restrains Ochanomizu so he cannot interfere and brings Astro back to life modifying him.

Tenma underestimates exactly what Astro's modified personality will be like though and Astro declares Tenma's lab a place for robots only. He drags both Tenma and Ochanomizu outside refusing to call Tenma his father. Ochanomizu tells him he has a true family of robots like himself. A father, mother, sister and brother who are all locked up in the ministry's warehouse. Astro's old ability to know when humans are lying tells him that the Professor speaks the truth. So he awakens the biggest and strongest of all Tenma's robots to help him break into the ministry and rescue his family. The Professor tries to reason with him but it's no use.

Although initially upset about the way Astro treated him, Tenma realizes that Astro is on his way to conquering and ruling the world just like he wanted him to and laughs in triumph. But Ochanomizu vows to find a way to restore Astro to normal if it's the last thing he ever does.


Dr. Tenma's personality has changed from the way he was in some other stories. When he appeared to give Astro some help in the Greatest Robot in the World in Volume Three he was rather very kind and friendly towards Uran. Furthermore according to the Astroboy Tales saga in Volumes Six, Seven and Eight he stole Astro's parents only to train them to be good robot parents for him. But now he's apparently gone insane wanting his son Astro to become king of the world and calling his robot family useless junk. He tells Ochanomizu that the ministry made them for Astro without his, Tenma's, permission and they should rightfully be turned into scrap. In actuality this characterization of Tenma isn't all that much different from the version of him that is used as a regular villainous presence in the 2000's animated series.

This is the first volume to be specifically continued like a serial into the next volume since the three mentioned in the above paragraph.