Demons exist in our world. Known as "Viruses," they are shells of men and women, sad yet fearsome beings cursed with an insatiable hunger for human souls. The only thing keeping the innocent alive are the Venus Vanguard, an elite group of hunters tasked with the extermination of Viruses. Lucia is their top killer, cold, calculating, and a deadly shot. Fate shines on Lucia when her path crosses Sumire Takahana, a young student with the ability to become a living anti-Virus. Theres just one problem with the Vanguards newest recruit when she enters into a rage, theres no stopping her!