It all begins with the story that was left untold—the earth-shattering incident where Renton's father disappeared. With the mysterious pilot Eureka by his side, only Adroc Thurston could undo his own mistake, sparking the event that changed everything and earned him the title of a hero. Now, ten years later, Eureka lies in critical condition as Renton leaves the crew of the Gekko. But when he finds himself in the care of his father's old friends, he has a choice to make. Either stay with the loving family he's always wanted, or earn the love he seeks.

Renton, son of scientists, and Eureka, a girl who can't live under the sun, are raised together when very young and become very attached to each other. One day, Eureka is taken away. Powerless at the time, Renton vows to rescue her. He enters the military and is soon is assigned to the Independent Youths Unit 303 of the First Mobile Forces thanks to his exceptional performance alongside his Nirvash, a bio-mechanical armor/control system. Unknown to Renton, lies a plot to extinguish the alien invasion that is currently happening involving not only him, but Eureka too.