In the future, mankind is divided between two powers: Union, and Deague. For the young Sarah Werec, watching her dearest brother Ralph depart for the front lines of the war was a fate worse than death; for even if he were to survive, the 130 light year distance between them dictates that even if he were to return, she would be long since deceased. Thus, in an effort to see her brother again, Sarah sets out to become a pilot of the Strain – Union’s mecha force; but on the eve of reaching the first step to her goal, her only chance to succeed is stripped from her. Haunted by the many ghosts of her memories, Sarah must now endure an endless series of sacrifices as she struggles to discover the truth about her brother...