After a lifelong petty thief named David finds himself in the middle of the bloody scene that was his family home, he is approached by a mysterious girl with a taste for sin. The mystery girl tells David the world he is living in is a lie filled with monsters beyond his wildest nightmares. David also finds out he is not the simple human he has grown up believing he is, with a task set forth for him no living being could possibly succeed in completing. Will David be able to rise to the occasion and save the world from absolute destruction, or will his blood tainted by a terrible lineage betray him by turning him into the very evil he is trying to destroy?