Natsume is invited to go to a pottery classroom with Shigeru. It's being held in an inn where he once stayed. When he goes there, he meets an old friend: the young fox child he once saved.

Nyanko-sensei falls into a well and discovers that there is a barrier inside it, as well as Nanase, Matoba's assistant. She is looking for a certain stone with a youkai she had sealed in it, and tells Nyanko-sensei the story of how she met the youkai to pass the time.

On a rainy day, Natsume meets a young girl youkai. Her name isn't in the Book of Friends, but she wants his help anyway: she wants him to find a man she met once. The man couldn't see youkai normally, but a mischievous trick of the weather let him see her for just one day. For the next fifty years she visited him, hoping he'd see her one more time, but he never did. Now he's vanished. Can Natsume find him for her?