Inuyashiki Ichiro is a middle-aged, friendless man with an uncaring family. One fateful evening, he is struck by a mysterious explosion in a public park, which is of extraterrestrial origin, and his body is replaced by an incredibly powerful, but still outwardly human, mechanical body. He quickly realizes the extent of his body's powers, and after saving a homeless man being beaten by a pack of teenagers, he decides to dedicate himself to doing good, using his powers to heal those with incurable diseases and fight crime.