Earth in the modern era is now filled with intelligent combat robot systems called Mobile Suits which are used for security as well as combat in outer space and across the planet against A Alien called Exorcist, A male figure named Kael is the co-pilot of a white combat robot named Zero, whose identity is kept secret by Kael himself.Zero is actually a very powerful legendary robot The robot can only communicate with Kael, not with others.Until this robot lacks 1 more person as an energy cockpit That is, humans who enter virtual hologram mode as the Cockpit of the robots' power. Kael is looking for the right person Several candidates recommended by his superiors were always rejected by Kael because they were not the people he had chosen. Until one day at a student academy Aurora University of Technology, The figure of a girl named Elira, who is a former Cockpit, has trauma when entering a mobile suit.Considering that Elira herself was one of the cockpits that fought on the planet Uranus His mobile suit partner died in battle, which traumatized him to this day.