On their way home from school, Lil'Pri runs into their classmate, Natsume Mahiru, and her little sister, Manatsu. At close glance, Manatsu has a bit of a resemblance of a witch, which reveals that they are going participate in the costume festival where everyone dresses up however they want and parades through the Hanasaki District. Manatsu wants to be a witch while Natsume wants to be a vampire...