Inventor Goro Ibuki creates a humanoid robot named Jet Jaguar. It is soon seized by an undersea race of people called the Seatopians. Using Jet Jaguar as a guide, the Seatopians send Megalon as vengeance for the nuclear tests that have devastated their society.

• TOHO
• Toho Eizo Co.
• Katsuhiko Sasaki
• Hiroyuki Kawase
• Yutaka Hayashi
• Robert Dunham
• Kotaro Tomita
• Ulf Otsuki
• Gentaro Nakajima
• Sakyo Mikami