In this world, the forces of Hell won the decisive war against Heaven long ago. The victorious devils rewrote history and redesigned society around their victory: good and evil were reversed. The bat-winged descendants of the devils form the ruling class; the white-winged descendants of the angels are treated as subhuman slaves. In this society, love is considered the most serious crime, and anyone found guilty of love or kindness is actively hunted and punished for it.