Tetsuwan Atom (1980) - episode 3 - 14 Oct, 1980

Toby is enslaved by a robot circus owner and is forced into manual labor, but befriends a young circus worker named Kathy. When Boynton's associate, Professor Elefun, comes to fetch him but the ringmaster refuses to surrender him, Kathy does the best she can to save the boy robot. It is during this episode that Toby receives his new name, "Astro," and his characteristic red boots. (Source: Wikipedia)