Miyu is an eternally youthful, 13-year-old vampire. Her peculiar appearance—golden eyes, pale skin, and hair tied with a ribbon in a strange fashion—are concealed during the day. She searches for the Shinma, the god-demons with mysterious forms and powers who prey on humans. Miyu is the Guardian, or Watcher, whose duty it is to return the Shinma to the dark by her power to call forth fire with which to burn them.

Her only companion, friend, and protector is Larva, a Western Shinma who is bound to serve her. Together, they hunt stray Shinma across Japan and across the ages. How Miyu became a vampire is unknown, as is how and why she became the Guardian. However, more mysterious is the gift she bestows on the people she feeds from...