Assiah (Earth) and the upper levels of Hell (Gehenna) are mirror images of each other. As mankind polluted and destroyed the Earth the lands of Hell also began to weaken. Taking advantage of their creator’s sleep and the weakening of their enemies the angels of heaven wage war on the Evil race, wiping most of them out.
In doing this the angels fighting the war are corrupted. They commit vile crimes and murders under the name of God and righteousness. This deeply goes against Alexiel’s morals. She feels that the Evils are more pure in their actions since they do not put up a charade of purity to cover their crimes. She joins the Evils’ side of the war and declares an official revolt against God.
Setsuna Mudo is a problematic delinquent high school student, who is in love with his sister. To add to his problems, he is also discovered as the reincarnation of a fallen angel, which gets him caught in the complex war between heaven and hell.