In the future world, due to the loss of his beloved son, the genius scientist Dr. Tianma (voiced by Nicolas Cage Nicolas Cage) created the robot Astro Boy (voiced by Freddie Highmore Freddie Highmore) to use it as a substitute for his son and find comfort. Although Astro Boy has the emotions and memories of the doctor's son, and advanced programs are constantly improving his emotions and making him compassionate. However, the doctor has never been able to accept the pain of losing his son, and he can't treat Astro Boy correctly, and thinks he is not a human being and abandons him. Astro Boy has become a homeless vagrant, and is also wanted by the military, and was eventually caught. The military asked Dr. Tianma to take away Astro Boy's energy and turn it into an energy source for military robots. At the last moment, Dr. Tianma suddenly woke up and assisted Astro Boy to escape. Faced with the military's pursuit and interception, Astro Boy rose up to resist, and finally a shocking war was about to start. During his continuous journey, Astro Boy gradually grew up. He accepted his design as a combination of machine and human, and took on the responsibility of the survival of all mankind.