God is dead, and the end is coming unless the fallen angel Alexiel can reawaken and prevent it. But years ago, as punishment for her defiance to god, Alexiel's body was sealed in a crystal, while her soul is continually reincarnated as a human being that will die a young and violent death, again and again, as an outcast from society -- despised and rejected. This time Alexiel's soul have been reincarnated into a delinquent teenage boy named Setsuna Mudou -- the Messiah prophesied to save humanity in the Black Book of Revelation. However Setsuna does not care for the coming battle between Heaven and Hell but only for his love... his blood sister Sara Mudou. Beginning the story of angels, demons and a lost God.