In the year 2061, Shichirō Ōshima awakes from a sleeping machine which his father, Prof. Ichirō Ōshima, invents. Prof. Ōshima saves Shichirō from a war using hydrogen bombs by his sleeping machine. Earthmen, who are afraid of hydrogen bombs, construct a large island in space with artificial satellites. Aliens from outer space try to conquer earth. Shichirō joins the earth defense forces. He is the 7th person who is immune to hydrogen bombs and named as "Number 7."