1212 A.D. During the Crusades, an innocent soldier finds himself betrayed, and leaps to his death, vowing to return as a fallen angel. Present day. Reborn as a woman named Aiko, the soldier rises as the military leader of a new Crusade, successfully unites the world and abolishes all religion. Haunted by memories of a past life, Aiko travels backwards in time... and finds herself caught in an incredible battle to save the future.