Previous to the storyline, three armies - the Garan Army, the Kiba Army, and the Hachiryokaku (Aira Army) - battle for complete control of the remote Machine Island's limitless resources. To stop the chaos bleeding out to neighbouring countries, the worldwide government, WSO, erected a "Gravity Curtain" to keep the three factions imprisoned on the island.
Years later, the WSO scientist realises the gravity curtain has become unstable; when it eventually breaks down, the explosion will destroy the planet and all life on it. To prevent this, the elite Skull Force is dispatched to Machine Island to shut down the reactors powering the curtain.
Ken Kaido and Ryo Magami, the two pilots of the Mazinkaiser mech, are sent to do recon. They each use different weapons when they're in charge: Ken uses the Ganzantou, a massive broad sword, while Ryo uses the Breast Triggers, a pair of hand guns that are attached to Mazinkaiser's chest.
To close down the reactors, Ken and Ryo have to defeat three armies. Can they succeed?
Anime production is by Actas, whose shows include Ex-Driver and Shin Megami Tensei Devil Children. Media Blasters has acquired the North American rights to the show and announced a tentative May release for the DVD.