The cartoon follows the adventures of a boy named Tetsuro, who destroys robots in an effort to avenge his parents’ deaths. The robots have taken over the universe and rule it with an iron fist. Tetsuro, a boy from a small, remote town, finds himself in the heart of an ultra-modern city, where the “Megapolis” planetary station is located. The “Galaxy Express 999” departs from this station, and Tetsuro tries to board it. He steals a ticket, and the mechanical people’s police try to catch him. Tetsuro is unexpectedly rescued by the mysterious Meitel, with whom he will travel together on the “Galaxy Express 999.” The boy wants to take revenge on the mechanical people—specifically Count Mecca—for the death of his mother, who was killed during a manhunt. He manages to kill Count Mecca, but Tetsuro decides to travel to the planet Andromeda, where a factory producing humanoid mechanical people is located. Upon arriving on Andromeda, even more thrilling adventures await him and Meitel…