You're one of the children in Japan who survived the virus that killed most of the adults. You're very powerful and skilled for a kid your age. Some vampires attacked you, and you somehow managed to kill them all with your sword and hands. You were walking away when you heard the sound of yelling. You went to check it out when you saw Yuuichirou, Shinoa, Shihou, Mitsuba, and Yoichi were getting attacked by some vampires