The Earth has been targeted for invasion by the alien Cthuwulf. A young girl, Nagisa Kano, becomes the key to Earth's defense when she is forced to become the partner of Iczer-One, a lone rebel who is battling the alien invaders.

The Earth has been targeted for invasion by the alien Cthuwulf. A young girl, Nagisa Kano, becomes the key to Earth's defense when she is forced to become the partner of Iczer-One, a lone rebel who is battling the alien invaders.