Great Mazinger is the second entry of the Mazinger trilogy. Several millennia ago, a powerful civilization named Mykene thrived in the Greek island of Bardos. To defend their island from invaders, they employed metallic giants that blasted tongues of fire from their chests. However, an earthquake destroyed their island and the Mykene disappeared. For a long while it was believed they perished right then, but it was false. In reality they were forced to seek shelter underground, and a lot of them grafted their heads into powerful mechanical bodies to survive. However they longed to return to the surface again and getting the sunlight, fresh air, and unpolluted water back.