When Natsume was younger, there was a big tree in his school road, and a female spirit lived on the tree. She was often teasing him, but he was too young to understand her behavior.
Natsume and Tanuma help to clean up a storehouse of Taki family. There are a lot of rare items, because her grandfather had studied spirits. Natsume notices one of talisman kimonos is lost.
With the help of Natori, Natsume was looking for someone who robs the spirit's blood. During the investigation, Natsume meets the young head of a famous exorcist clan, Seiji Matoba.
An unknown stone is in the school bag of Natsume who came home, suddenly it murmurs something. Hinoe kick it out of the window luckily, but Natsume has a bad feeling.
Natsume reluctantly participated in a party of some spirits he has befriended. The spirits drank, got excited, and then ask Natsume to teach a human child's play.
