Astro Boy (鉄腕アトム Tetsuwan Atomu, lit. "Mighty Atom") is a remake of the 1963 anime with a darker take on the story of the manga from which both are based. The series aired 52 episodes in Japan, and was edited down to 51 in English releases. The original run aired from the first of October in the year 1980 till the 23rd of December the next year.
The first episode takes place in the year 2030 in Tokyo, Japan. Dr. Tenma, the Minister of Science, is attempting to create a robot capable of expressing human emotions. After his fourth failed attempt, Tenma is approached by Skunk Kusai, a man who offers him an "Omega Factor" circuit which, when installed, will humanize a robot. After rejecting Skunk's offer and throwing him out, Tenma's nine-year-old son, Tobio, suggests his father make a robot shaped like a child.
Inspired by his son, Tenma sets off to the Ministry of Science to work, forgetting his promise to take Tobio to an amusement park. Upset by his father's neglect, Tobio drives an aerocar home but crashes into an oncoming truck, dying in the process. Just before he dies, Tobio makes his father promise to name his boy robot "Tobio" and make it the strongest robot in the world, while still loving it like a son. Tenma then creates a 100,000 horsepower (75,000 kW) robot capable of flight, equipped with lasers and machine guns. However, Skunk obtains the blueprints, duplicates them, and takes them to the evil Count Walpurgis, who aspires to put the Omega Factor into a super robot and use it for world domination.
Afraid of the potential threat Tenma's robot son could pose to humanity, the Prime Minister of Japan orders the robot dismantled by the next night. Tenma, however, secretly finishes constructing the robot that night, only showing his two assistants that "Tobio" exists, and takes him home to raise him. After various mishaps with raising the robot, Tobio's mind suddenly goes blank, his eyes start blinking red, and he is summoned to wait in the middle of town. Atlas, Walpurgis' new super robot, had been activated and was connecting to Tobio. When the connection process fails, Tobio regains his senses, only to come under attack from a robot disposal tank piloted by Tenma, Honda, and Ushiyama. Something goes wrong and the tank malfunctions and goes berserk. Tobio recovers and saves everyone in the vicinity. Recovering in the hospital, Tenma realizes the public will discover that Tobio exists, and decides to take Tobio on an ocean cruise to America.
Tobio struggles to control his strength. After a disastrous meal on the cruise, Tenma disowns Tobio. Tobio hides on deck and is tricked into signing himself into a contract of slavery to the ringmaster Hamegg, who runs the Robot Circus. Tobio spots Atlas nearby and tries to attack him, but Tobio loses most of his energy in the process. Hamegg then shuts him in his suitcase. Tenma soon regrets his actions and begins searching for Tobio. At the circus, Tobio is renamed "Mighty Atom/Astro Boy" and is cruelly treated by Hamegg, but taught and cared for by a performer named Kathy, who shows him kindness and compassion. Professor Ochanomizu, a local scientist, discovers Tenma's lost robot at the circus and, with Kathy's help, smuggles Astro Boy out of the circus. Professor Ochanomizu becomes the new head of the Ministry of Science. From there, Astro Boy learns more about the world and becomes the defender of Tokyo and beyond.