In a time of war, Sara Werec yearns to follow her brother Ralph into the stars and take up the Union cause in their endless fight against the Deague. Ralph is a legend among the ace pilots known as Reasoners – warriors who bravely steer their advanced mech units headfirst into combat.

Sara’s hopes are soon to be fulfilled, but the horrors of war spare no one. On the eve of Academy graduation, Sara loses everything when Ralph commands a Deague assault force in a surprise attack against the school. Amid the smoking rubble of her dreams, Sara Werec boldly undertakes a new mission: Confront Ralph to reveal the motives behind his betrayal and put an end to his treasonous ways by any means necessary.