A mysterious stone known as Skull Stone is scattered across the planet, and it holds the power to reveal the location of the largest deposit of gold in the world. The Doronbo Gang, the three villains, are searching for the Skull Stone. Standing in their way are Gan and Ai who, teamed up with their large mechanical dog Yatterwan, become the masked heroes Yatterman-1 and Yatterman-2.—Moh X