Setsuna Mudo is a troubled sixteen-year-old dealing with bullying and forbidden feelings for his younger sister Sara when celestial and infernal beings both come looking for him. Angels insist he is the reincarnated leader Alexiel; demons claim he once led their rebellion against God. Caught between two sides that claim him for different reasons, Setsuna has to decide which version of his own history to believe. This OVA adapts only the opening arc of the manga.