Gigantor is an American adaptation of the anime version of Tetsujin 28-go, a manga by Mitsuteru Yokoyama released in 1956. Jimmy Sparks controls a gigantic, powerful robot and uses it to fight crime. It debuted on U.S. television in 1964. As with Speed Racer, the characters' original names were altered and the original series' violence was toned down for American viewers.