Astro Boy was created by Doctor Boyton when his son Toby died in a car accident. Astro is an exact match for Toby. And was originally called Toby by his "father". When Astro was first built, Doctor Boyton wanted to keep him a secret. But people eventually found about him and he became a hero. Astro was separated from his father during a cruise. Astro saved the ship from some ice burgs, when he returned, his father had disappeared. Astro was tricked into signing himself over to a robot circus. (myanimelist.net)