Haruka is the girl you have been dating, in what have been the ideal relationship, until disaster struck. Haruka has been infected with "the sickness", a virus that lies dormant inside the human brain, waiting until it's victim were bitten by another infected, which would then turn them into mindless zombies. Fortunately, or rather, unfortunately, it seems Haruka is still able to retain some form of consciousness, even after the infection has taken full control over her bodily functions.