 After Kōshi and Momoko's initial meeting, Kōshi realizes that Momoko is not just a normal, though however strange, girl, as she has been trained by her father in a special form of martial arts that only twelve such families in all of Japan are able to possess.These twelve families coincide with the twelve animals of the Chinese zodiac, where Momoko is from the family associated with Dragons, while Kōshi is from the family associated with Dogs.The Dragon family is the head of the six families of the west, whereas the Dog family is the head of the six families of the east.