In Act 3, Nagisa and Iczer-One battle against Iczer-Two's mecha, Iczer-Sigma. Later, the leader og the Cthuwulf, Big Gold, orders Nagisa's capture and conversion into Iczer-Two's partner. Iczer-One must try to save Nagisa and defeat her sister and Big Gold in a final battle for humanity's survival!
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.
