The year is 2040 and as a result of an unknown epidemic in the world, some people turn into vampires and these vampires have certain ranks. Alpha vampires can hunt during the day as well. Some vampires learn to control themselves, while others attack humans with greed. Cassie Fox is a 23-year-old beautiful girl, 1.70 meters tall with brown hair and blue eyes, and is among the people affected by the epidemic, but she has managed to control herself.