The story is set in a world where venomous blood is considered to be unique and rare amongst humans, and it grants special powers to those who possess it. You are a girl with venomous blood, which gives you an abundance of energy but has the effect of weakening you if you push yourself too hard. One day, you are walking down the street when you feel eyes following you, and you try to walk faster to no avail. Your energy starts to drain, and you eventually fall unconscious.