In a fragile world plagued by a weak government and lawless syndicates, the mafia operates with absolute impunity, burying their sins in the shadows. To counter this unchecked evil and restore a grim balance to justice, a merciless and uncompromising force emerges from the dark. Operating without hesitation, they are humanity's final resort—an elite enforcement organization known as Red Raven, where the singing of the raven signals the absolute end for the guilty.