Dr. Kochin, a specialist in biotechnology, gathers the Dragon Balls inside his laboratory with the goal of freeing his master, Dr. Uirou—a mad scientist obsessed with world domination who has been trapped forever in the never-melting ice of the Tsurumai-Tsuburi Mountains. While searching for the Dragon Balls, Son Gohan and Oolong arrive at the scene and are ambushed by several creatures called "Bio-Men." Piccolo, who is training nearby, tries to rescue them but is attacked by three mysterious warriors. The ice beneath them breaks, cutting the fight short and burying Gohan and Oolong.
After they regain consciousness, they return to Kame House only to encounter more Bio-Men, who demand that Muten Roshi follow them. When he refuses and easily defeats the creatures, Dr. Kochin becomes interested. Believing Muten Roshi to be the strongest man in the world, Dr. Kochin takes Bulma hostage, forcing Roshi to agree to accompany him on mysterious plans involving his master. Who are Dr. Kochin and Dr. Uirou? And what is their true goal?