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Astro Boy Wiki

This article is about the character. For the manga, see here.

Pluto (プルートウ Purūtō) (also known as Bruton in the 1980's version) is a giant metal fighting muscular robot with horns and red stripes on his face. He was built to destroy the strongest robots in the world, including Astro. At first, he wants nothing more than to fulfill his duty but soon he realized that programming isn't everything and befriended Astro. He has Kokoro. He once captured Uran and she was mad but then they got along.


Pluto is an enormous, burly humanoid robot with a design that is reminiscent of a demon. His metallic exterior is jet black in color, with red accents on his cheeks that resemble tribal war paint. His imposing stature is further accentuated by a pair of long, bull-like horns, which stick out of the sides of his head and curve straight upwards.



1963 Series


A Sultan wants to be the ruler of the robot world, so he hires a scientist to build a robot. It must have 1 million horsepower, plus various powers in order for it to become the "Strongest Robot in the World". Named Pluto, his first target is a Swiss mountain robot with 135,000 horsepower named Montblanc, which was an easy victim as Pluto was a complete stranger to him and he did not suspect the attack. With Montblanc finished, Pluto then goes on to fight Astro, who was not at home (plus Professor Ochanomizu insisted on Astro not fighting, much to the annoyance of Uran). As Astro himself does not engage in battle, Uran pretends to be Astro in order to fight Pluto, however, she is no match for Pluto's horsepower and strength. Overcome, Pluto holds Uran captive as a way of forcing Astro to fight. Enraged, Astro follows in hot pursuit. Meanwhile, Pluto then goes to fight North MK II, a fearsome battle robot that acts as a butler. North is no match for Pluto's strength, being defeated almost instantly.

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Seeking Astro, he and Astro again meet (which so happens to be in Turkey) which by chance is the residence of the next robot, Brando. Sharing similar strengths and weaknesses, Pluto just defeats Brando - and only just - and as a consequence, he was heavily damaged and could die if his masters do not come instantly. In order for them to come, a button on his chest has to be pushed which sends a distress signal. However, as there is no-one else nearby and he himself is unable to move his arms, the only way for the button to be pushed is if Astro pushes it. Pluto quickly hands over Uran and begs Astro to push the button. After much thought and consideration, Astro agrees. His masters come to collect Pluto and plant a suicide bomb in his chest; should someone defeat him, that someone would also be destroyed. Pluto then faces his next target, a German robot detective named Gesicht, made out of a unique material named "Zeronium", which takes the form of a protective metal alloy. Gesicht's machine guns prove ineffective against Pluto's shield, and he is also destroyed.

Astro, who was informed of the battle beforehand and sees the result of Gesicht on the news, realizes that Pluto must be stopped as no robot is a match for Pluto. However, he realizes that Pluto is simply too powerful for even him so he thinks up a solution and asks Ochanomizu to increase his horsepower instantly. Flying over to the ministry of science, Astro finds Ochanomizu "already busy", since he has tracked down Pluto's hideout by monitoring his movements, and flies over by plane to the hideout. Unable to convince the Sultan, he is held captive and the only way where he allows him to go is when Astro fights Pluto. Ochanomizu reluctantly agrees, and Astro and Pluto meet in the desert. Unfortunately, it is right in the middle of an oil field. If the oil explodes, the impact would be massive so Astro refuses to fight, and as a result, Pluto holds Astro in his hands and prepares to tear him apart, but then spares his life as he remembers that Astro saved him once. Reminding Astro he would only do it once, Pluto takes off and fights Heracles, a Greek gladiator robot with a high sense of nobility and bravery who soon becomes another victim of Pluto. Meanwhile, at Astro's place of residence, he receives a phone call from the southern continent.

The caller is Epsilon, who except for Astro, is the sole remaining member of the strongest robots in the world. Epsilon is a robot with a gentle personality that takes care of kindergarten children. As she needs sunlight, Pluto promptly chooses their day of the battle on a stormy day and therefore Epsilon is not at her full strength when they fight. Epsilon is also ultimately destroyed after risking her life to save a lost infant. Astro arrives too late, and the duo prepares to fight to the finish; the scientist, however, refuses, claiming the battle would take place on the Mountain of Tears, a volcano. While the battle rages on, the volcano explodes. Astro quickly tries to stop an impending explosion but fails: two robots are needed to effectively cover up the volcano itself.


Pluto, after watching for a while, eventually helps Astro, implying that he has learned to value human life. The threat is stopped, however, and the scientist reveals his secret invention, a super robot named Bora with 2 million horsepower. Pluto, realizes that defeat is unavoidable, asks Uran not to forget him and then sacrifices himself. Bora and Pluto are then involved in an explosion and while Pluto is destroyed Bora emerges unharmed. Astro fights Bora by tearing the robot apart. Afterward, it is revealed that the scientist isn't human (much to the surprise of the Sultan) but his former robot servant, who built Pluto and Bora to show that horsepower isn't the only way to win a battle. He was killed by Bora, the only robot with more horsepower than him.

Pluto also briefly appears in the final episode of the 1963 Astro Boy series as a flashback.

1980's Series

Known as Bruton in the 1980's series dub, he was created with the sole purpose of defeating the worlds strongest robots. However, the fights are shortened to quite an extent. The fight with Montblanc was originally a minute long, but it was changed to be less than a minute.

The color-remake is very faithful to the original 1963 version, leaving most of the story unchanged.

2003 series

2003 version

In the 2003 series, Pluto is shown to be the primary antagonist in the episodes The Rise of Pluto and The Fall of Acheron. Built by Shadow (a robot which is in turn built by Dr. Tenma) in order to help Astro evolve, he is shown to be often careless and heartless, with the sole thought of defeating his enemies and fulfilling his purpose (similar in a way to the 1980s series), and because of this does not display any sorrow or emotion to those who he has defeated.

Pluto's method of attack is a set of homing missiles located in his chest (unlike the horns he used in the 1980s series) as well as some other tactics (depending on the robot he is facing). Every time during battle, he is nearly destroyed, however always foils his opponent's method after discovering a "weakness" or a potential flaw that he could use to his advantage. He is also given the ability to analyze and detect these flaws.

Eventually, he develops emotions and a sense of kindness, shown when he sacrificed himself in order to stop Acheron, a robot duplicate of himself, from harming Astro and Zoran(whom he shares a relationship with). He was later rebuilt during the robot war near the end of the series, where he was one of Astro's allies.

The Pluto episodes are actually a 2003 remake of The Greatest Robot in the World story arc, and Pluto is actually the 2003 version of the character Bruton in the 1980s series but a little bit more muscular. Because of this, the characters Pluto fight are also remakes (e.g. Epsilon is actually Photar), although the final character that defeats him is different (he was defeated by Acheron in the 2003 series, Bora in the 1980s). His purpose also differs dramatically from the two series. Built by Shadow for the same purpose, he was made for Astro to "evolve".

In Other Media


Pluto in the Manga

Urasawa's Pluto is significantly darker as he is seemingly capable of murdering humans and robots, and is extremely powerful, possessing some control over the weather by generating fierce tornadoes. He goes on to kill the entire "Bora Investigation Squad", always leaving behind a corpse with horn-like protrusions next to it.


Despite this, "Pluto" is actually Sahad, a peaceful, quaint, robot with a strong affinity towards nature and who wished to fill his desolated country of Persia full of flowers. He was created by the Persian Minister of Science, Dr. Abullah. Devastated by the 39th Middle-East War, with his country left in shambles and his family dead, Abullah came to harbor an intense hatred and vowed revenge. He died during the war as a result of a bombing, but before dying, he left the genius Japanese scientist, Dr. Tenma (creator of Atom, the story's version of Astro Boy), with a chip containing part of his brain, and full of Abullah's hatred towards the world. Tenma used the chip to awaken the perfect AI he and Abullah had been working on (due to being programmed with 6 billion personalities, the robot would take an infinite amount of time to simulate all the possibilities and would never awaken; Tenma had theorized that this could be overcome by programming intense, polarizing emotions into it, such as hatred, rage, and despair). The robot awoke, and despite believing itself to be Abullah, it also created a second personality, "Goji".

"Abullah" proceeded to create Pluto, and inserted Sahad's AI into the robot. Goji went on to create "Bora", another, much bigger robot, which was left underground; his plan was to insert his AI into Bora, and tunnel underground, causing a massive eruption that would destroy the planet.

Atom, who had been left in a similar state to that of Tenma's perfect AI due to an attack by Pluto, is reawakened by Tenma, who inserts a chip containing Gesicht (the main character)'s hatred and a recording of his moment of death (as he was defeated and then destroyed by Pluto). Initially, he behaves oddly, but after some time seemingly reverts back to his former self. After learning the whole truth of Gesicht's case, he heads to the source of the cataclysm in hopes of stopping it. He comes face to face with Pluto, who attacks him. At first, Atom is overcome by Gesicht's hatred and attempts to destroy Pluto, citing all the robots he'd killed did not want or deserve death and rips off Pluto's horns and one of his arms in the process. However, he then hears Gesicht's last words in his mind: "Nothing comes from hatred". Suddenly full of understanding, Atom and Pluto cease their attack on another and proceed to lie down for a few moments. Soon afterward, Atom goes to disarm Bora, with Pluto (whom Astro has begun referring to as Sahad) at his side. Bora attempts to dissuade Sahad, who rejects him, stating that his father has long been dead, and the AI controlling Bora is nothing more than a fake. He ends up sacrificing himself, saving Atom and the world from the disaster in the process.


  • Pluto is the final boss of Tetsuwan Atom for Super Famicom, though he is not implied to have a friendship with Atom and no dialogue after his defeat since all is left is his scrapped remains. Neither version of Bora appears.
  • Pluto is the final boss of the scenario "Birth" in Astro Boy: Omega Factor. He is one of the world's strongest robots who served Shadow and is fought after Epsilon.
  • One of the final panels in the adaptation of The Greatest Robot in the World: "Pluto", seems to be a remake of one of the last panels of the original The Greatest Robot in the World manga.
  • In the show Jetter Mars, a character very similar to Pluto appears named "Mad Mask", who is even called the Greatest Robot in the World, which is the name of the episode Pluto appears in the Astro Boy series.
  • Pluto is named after the Roman counterpart of Hades, the Greek god of the Underworld. This name is fitting, as his design is seemingly based on traditional artistic depictions of demons.