President William Stone or simply Stone is the ex-president of Metro City and the main antagonist in the film]
In the film he was re-running for President and funds Dr.Tenma and Dr. Elefun's research at the Ministry of science. He wants to built a robot called the Peacekeeper to defend the city from a supposed attack from the Surface and wanted it to be a fighter not a lover, despite the fact no indication has ever been made that they would do so. The Blue Core, pure positive energy sphere, was prepped for the robot but Stone, who had heard the blue core was essentially a manifestation of peace and life instead chose the negative Red Core.
Later on he flew a Command Ship. His troops and his right-hand man got a radar signal of the Blue Core. As the rest of the troop, he is shocked to see Astro Boy, then still known as Toby, for Astro's resemblence to Tenma's dead son, he also noted how Tenma "must have lost his mind". He sent Stinger Interceptors to capture the young robot. When it fails to do so, he mercilessly orders to bring in the Spirit of Freedom, a powerful military airship, to shoot Astro. This causes him to fall to the Surface, which in turn sparks Stone's determination to capture him, being obsessed with the idea that bringing back the Blue Core to power the Peacekeeper will get him re-elected.
He then went to Dr. Tenma's apartment to arrest both Tenma and Elefun, but soon releases them after Tenma agrees to deactivate Astro when Stone brings him.
He arrived at the Robot Arena in his shuttle to capture Astro and take him to the Ministry of Science to have the Core removed. He clearly thinks little about robots, believing them to be machines that must do as it is told, and treats Astro like one.
After Tenma removes the Blue Core, Stone's words was the drop that spilled the cup. Tenma betrays Stone and reactivates Astro. Stone is seen glaring at Tenma as he watches his son fly away. He then loads the unstable Red Core into the Peacekeeper which later absorbs him, merging his mind with its own. Controlling the Peacekeeper, Stone wrecks havoc in the city. He fought Astro but after he obtains both Astro and the Blue Core is forced to release Astro due to the merging of Red and Blue Core would kill them both. Astro flies back into the Red Core, thus destroying the Peacekeeper at the cost of Astro's life.
He survived the destruction caused by the merging, but was kicked by Grace and arrested by his men. He probably went to jail and got tortured and killed by his men after this.
It is said that Stone flunked out of college.
He is hinted to be quite physically strong when he easily beats his sidekick in a hand wrestling contest, saying he "wins again".
He somehow has millions of guards which look like stormtroopers and clone troopers from Star Wars.