In the year 2010, the first manned mission to Mars returns to earth. During re-entry, something goes horribly wrong, and the craft explodes, scattering debriss on the earth below. Shortley afterwards, seemingly related to the loss of the Mars mission, strange creatures dubbed 'Ancients' begin to attack the earth. An agency called AAST is formed to fight them, deploying a crack team of all-female specialists in swordplay, firearms, and intelligence. But the key to defeating the Ancients is not these skilled operatives, but Takeru, an inexperienced high-school boy who is the only person capable of wearing the mysterious MARS power suit, the only weapon that can go toe-to-toe with the Ancients in combat. Forced by his father to wear the MARS suit, Takeru is thrown into a deadly battle for the earth.