Prior to the events of the anime, the three factions - the Garan Army, the Kiba Army, and the Hachiryokaku (Aira Army), battle for total dominance of Machine Island, which they occupy. The island is basically a prison, isolated from the rest of the world. To assure total quarantine, a "Gravity Curtain" was formed within the island. Only machines created by the worldwide government WSO are capable of entry to the island. The island also contains vast amount of resources, allowing the three factions to create a near-limitless supply of giant robots for their respective armies.
The WSO has learned that the Gravity Curtain has reached an unstable status and will explode within 66 hours, destroying all of Earth and human life itself. Each of the three factions controls a part of the mechanism responsible for the Gravity Curtain's operation. Knowing the danger of disabling the Gravity Curtain and combating the various factions, the WSO decides to send the Skull Force. The Skull Force is divided into two squadrons - one of which is the 2 member-only Death Caprice Squad, composed of Ken Kaido and Ryo Magami, pilots of the Mazinger called Mazinkaizer SKL.....