In the distant future humans have spread beyond Earth and colonized planets across the universe, creating a New Frontier of man.
In order to protect these new settlers and maintain laws and regulations in the New Frontier, Earth’s Cavalry Command was created. Cavalry Command was in essence a military organization, maintaining an army and fleet of ships to protect the New Frontier. Within Cavalry Command was a unit of special operatives known as Star Sheriffs that functioned as field agents, investigating crimes and plots against the security of the New Frontier.
The main foe of Cavalry Command and the Star Sheriffs was a race of non-human creatures known as Vapor Beings (or Outriders) that jumped into our dimension in order to conquer it. They attacked the settlers, destroyed settlements and kidnapped humans in order to mine various metals or crystals from the soil.
Outriders were superior to humans in battle technology, possessing a legion of gigantic robots with uncanny firepower against which the space-going fleets of Cavalry Command were no match. In order to have a chance against such supremacy, Cavalry Command developed a prototype ship known as the "Ramrod Equalizer Unit" (or just Ramrod) that had the ability to turn from spaceship into a powerful robot that could fight the Outriders on equal terms.