The Greatest Robot in the World

The Greatest Robot in the World is the name of two episodes in the 1963 and 1980 series. It featured a remake in the '03 series and was the basis of the Pluto manga. this is the first anime to have a character to Cross dress.

Plot
A Sultan wants to be the ruler of the world, so he got an masked human scientist to help him create a robot with 200,000 horsepower. The robot, named Bruton, was then set to defeat the strongest robots in the world one by one, including Astro.

His first target is a Swiss mountain robot named Montblanc, which was an easy target because he did not suspect the attack. Afterwards, Bruton went to find Astro.

Astro was not at home, plus Professor Ochanomizu told Astro not to fight. Uran then pretends to be Astro, seeming to be no match and does not possess his powers, Bruton concludes that she is Astro's sister and holds her captive.

Bruton goes to fight Monar a fearsome butler robot, but again is easily overcome. Seeking Astro, he and Astro meet somewhere. as it would happen, it's the residence of the next robot, Brando, which Bruton overcomes, this time with difficulty. During the fight Bruton is severely injured, and begs Astro to push a button on his chest in order for him to live. Astro agrees. His masters come and collects Bruton and plants a suicide bomb in his chest; should someone defeat him, that someone would also be destroyed. Now for the next target: the great German robot Gerhardt. Gerhardt is made from a special material, but Bruton eventually defeats him also.

Ochanomizu finds Bruton's hideout, but Bruton's masters hold him captive in a underground vault, and he would only be released if Astro fights Bruton. Astro and Bruton fight, however Astro is almost beaten when Bruton lets him go, since Astro saved his life once, Bruton saves him - but only once.

Bruton goes to find Hercules, a Greek noble robot. He is soon destroyed.

The next target is Photar, a robot from the Southern Continent. Photar uses the sun as his power, but because of the weather there is little sunlight. His soft spot for children determines his fate. (he is very close to defeating Bruton when one of the children at the daycare he works at comes out looking for him. he saves the child and Bruton takes this opportunity to destroy him.)

Astro and Bruton then fight on the mountain of tears. During the fight, the volcano erupts, and Astro attempts to cover the crater with rocks. Bruton, after watching for a while, then helps him and the danger is stopped. Then Bruton fights his last opponent, Bora, a robot with twice as many horsepower as him. He is unfortunately destroyed in the battle, and Astro avenges him by fighting Bora and winning. the Sultan's "human" scientist then reveals himself to be an old robot servant of the Sultan's, and had built Bora and Bruton to show the sultan that horsepower isn't everything.

2003 series remake
The 2003 series remake has two episodes, The Rise of Pluto and The Fall of Acheron, and many of the more important characters either return or are replaced:
 * Bruton = Pluto
 * Mont-Blanc =Harley (though in the GBA astroboy game, a redesigned mont-blanc appears as a wrestling robot named Brontus, and is an opponent. He looks almost exactly like Montblanc except he has more combat abilities and shares some traits with Brando, including the ability to turn into a destructive ball.)
 * Monar = Monar (cameo)
 * Brando = Brando (cameo)
 * Gerhardt = Delta Red
 * Hercules = Hercules
 * Photar = Epsilon
 * Bora = Acheron

Pluto (manga)
A manga by Naoki Urasawa, which is loosely based on the plot. It revolves around Europol robot detective Geischt (Gerhardt) and is a more realistic retelling of the story.