Kazuki Yotsuga sees visions of a parallel world where giant robots clash, unnoticed by others. Introduced to Professor Ken Sanada by his daughter Mitsuki, Kazuki learns Ken’s quantum physics experiments may connect these realities. When Mitsuki accidentally triggers Ken’s portal device, Kazuki is thrust into the alternate world. Unaware of the shift, he’s nearly crushed by battling robots. During a skirmish, the Hartzenen robot crashes, and its injured female pilot collapses in Kazuki’s arms. Forced to take control of the robot, Kazuki enters the fray, discovering his unique ability to pilot it.