In Shijuku, near future, consecutive murders occur. The victims were deprived of their body fluid. They know a guy named Eko is the murderer. He used to be “Karas”, a guardian of the town, but before they knew it, he named himself Eko and began to revenge himself on human races.
Yurine is the person who directs Karas to save the town. In order to stop murder, she chooses Otoha as a new Karas. Then, a battle of two Karas begins.