Natsume and Nyanko-sensei found Natori's paper doll which time and place was written in downtown, Natsume worries about Natori. They go to that place, and then get to know a girl named Tsukiko.
Tsukiko is daughter of Natori's master Takuma. She asked Natori for help because something unusual has happened at Takuma's house since Takuma lost his ability.
Natsume's friends reflect on how they met him, and the difference he made in their lives. He's found a home, and he means a lot to the people who live there.
Natsume is surprised when a youkai comes to seek Reiko in gratitude. Years ago, the youkai's to-be-bride received freedom from her help, and now is about to be wed. They invite Natsume to the wedding.
Natsume talks to a teenage boy at the station, who turns out to be a youkai that left a human because of their feelings for one another. The boy wants to find her because he received a wedding invitation
A competition is opened to search for a famous researcher's sealed room and many exorcists are gathered. Natsume decides to go, as he may find information regarding the Book of Friends.
