Naoto Kurogane was a mostly ordinary high schooler who lived a peaceful life with his childhood friend Haruka Hayami. What wasn't ordinary with Naoto is that his right eye is a little special, it possesses a special ability, "Eye of the Hunter", that makes it possible for Naoto to see other people's life force in numerical values. But his ordinary days ended when he met a girl with such high life force that she couldn't possibly be human. The girl introduced herself as Raquel Alucard, a vampire. She ordered him to get the hold of the Azure. And so Naoto was dragged into a bloody battle surrounding the Azure. Source: BlazBlue Wiki