In his laboratory, Dr. Kochin, a skilled biotechnologist, collects the dragon balls with the intention of freeing his master, the crazy Dr. Uirou, who desires to conquer the world and is frozen in unmeltable ice at the Tsurumai-Tsuburi Mountains. While attempting to locate the dragon balls, Gohan Son and Oolong are attacked by Bio-Men, but Piccolo, who is training close by, comes to their rescue. However, Piccolo's fight with three mysterious warriors is interrupted when Gohan and Oolong fall into a chasm caused by the breaking ice. After recovering, they meet the Bio-Men again at Kame House, who demand the presence of Muten-Roshi. When he declines and easily overpowers them, Dr. Kochin becomes interested in Muten-Roshi, whom he believes to be the strongest man on earth. To force Muten-Roshi to join a mysterious plan involving his master, Dr. Uirou, Dr. Kochin abducts Bulma. What are Dr. Kochin and Dr. Uirou's motives? What is their actual aim?