Makoto Okazaki is your run of the mill high-schooler, a perfect bullying target und a closet pervert.
One night he decides to return a DVD to a friend of his and ventures out. He notices a person on a nearby rooftop. The person lunges at him before he is able to make sense of this, and bites into his neck, drinking blood.
At this point Makoto notices that the attacker is a beautiful girl. She asks him: "Do you want to die or become like me?" He decides to live...