The legend of Watt Poe, a mysterious whale said to give happiness, in a world destroyed many years ago by a nuclear war

The Iron Cross Army are sabotaging oil-tankers with the help of their monster, the Sea-Devil, a semi-mechanical anthropomorphic swordfish with an ability to shoot torpedoes from its mouth. Spiderman employs the help of the interpol agent Juzo Mamiya to help him stop the Iron Cross Army.