After the tragic death of his only son Tobio in a car accident, Dr. Umatarou Tenma, director of the Ministry of Science, orders his staff to build Atom, a robot modeled exactly after Tobio and endowed with unparalleled power and intelligence. Though Atom inherits Tobio’s innocence and playful spirit, Tenma soon realizes that the synthetic boy cannot grow like a human. Unable to accept Atom as the replacement for his son, Tenma attempts to forget the whole affair and, in his cold dismissal of the machine’s emotions, sells Atom to a circus that treats its performers as disposable tools. Despite his dire circumstances, Atom remains kind to both his mechanical peers and humanity, protecting all who are endangered. Then Dr. Ochanomizu, a visionary fighting against the mistreatment of robots, frees Atom from the circus. With Ochanomizu’s guidance and a chance to thrive in a society where humans and robots coexist, Atom devotes himself to creating a peaceful world while exploring the complexities of existence.