In a world where angels, devils, and humanity are locked in battle, Black Matrix 00 focuses on a young man who is searching for his kidnapped childhood friend. Black Matrix 00 begins with a mute man being adopted by a woman who nurses him back to health from some traumatic experience. This differs from a Harlequin romance in several ways. There is the matter of the man having white wings and the woman having black wings: in this world black winged people are dominant. The black winged people also pay more than lip service to Satan. As expected in a world where Satan is omnipresent, love is a Bad Thing and once the woman admits to having feelings for the man, they are forcibly separated and the man meets up with allies in prison. Then a number of Biblical allusions are run through in the course of a battle against the oppressive forces of Satan (though figuring them out from the Japanese may take some effort).