Casshan began his life as Tetsuya Azuma, the son of Kotaro and Midori Azuma. The former of his two parents was a scientist who turned Tetsuya into Casshan after Kotaro successfully revived Tetsuya's dog Lucky into a robot dog named Friender when Tetsuya volunteered to be turned into a neo human, despite the objection of his mother and father. Tetsuya volunteered to become Casshan due to another one of Kotaro's creations, Black King activated on his own and set out to conquer the world. In the 1993/1995 OVA remake, Kotaro and Midori are killed by Black King.