Baldr Sky — the life mission of freelance mercenary and simulator pilot Kou Kadokura is to catch those responsible for Gray Christmas, the tragedy that destroyed his once-peaceful life. So why can’t he remember anything? He wakes up in the middle of a bloody virtual battlefield, riding in a mechanical body with many questions on his mind. Who does this woman call him a lieutenant? Who can he really trust when there are so many gaps in his memory? As the war looms in the anti-utopian city of Suzushiro, everyone looks at Coe, a man with answers to questions from the world locked inside him.