A brutally talented kid with no past and a friend he'd die for walks into an empire that treats him like a ghost. The visual design is so deliberate, so layered with religious symbolism and baroque detail, that every frame feels like it's hiding something from you. Teito and Mikage's bond is the show's actual plot, even when the story meanders, because watching someone protect the one person who sees them as human costs something every episode.

Teito Klein is a soldier-in-training at the Barsburg Empire's military academy, where students wield a combat ability called Zaiphon. He is among its most gifted cadets, yet others mock him as a sklave, a slave who remembers nothing of where he came from. A fellow student named Mikage becomes his friend. While getting ready for his final exam, Teito learns something dark about his own past. He tries to kill Ayanami, a powerful official responsible for his father's death, but the attempt fails and he is imprisoned to await punishment. Mikage helps him break out, and Teito finds shelter with the bishops of the 7th District Church. Pursued by the imperial military, he hopes to recover his lost memories and learn why he may hold the power to change the world's fate. The action fantasy story blends that chase with mysteries surrounding the church, the Empire and the legendary Ghosts said to protect it.