There are two authorities that ruled the city; The royal family (werewolves) rule the day and the mafia organization (vampires) rule the night After series of fights and battles, the two authorities are unable to defeat each other so they decide to form a relationship with each other through marriage Sin and Richard were f****d to marry despite hating each other Sin and Richard were lovers by name not by heart but as the story goes on, Sin finds herself obsessed with her f****d mate