Professor Tenma creates a robotic boy modeled after his recently deceased son Tobio, believing that the invention can carry on his child's memory. He quickly realizes, however, that the robot can never truly replace the son he lost. Soon after its creation, the robot is kidnapped and taken to a robot circus in America. There, it is rescued by Dr. Ochanomizu, who brings it back to Japan and names it Tetsuwan Atom. The robot becomes Japan's crime‑fighting hero, yet its pacifist stance and childlike naivety frequently clash with the demands of battle.