Natsume accidentally releases a yokai named Madara who tells him about his grandmother Reiko's Book of Friends.

Natsume decides to return the names of the yokai with the help of his new bodyguard, Nyanko-sensei: a small yokai named Tsuyukami comes to get his name back, but the page with his name is stuck to the next page.

A yokai who lives in Yatsuhara comes to Natsume to ask him to capture a human; a classmate who recently moved to Yatsuhara named Tanuma starts asking about Natsume.

Natsume and his classmates decide to go ghost hunting at the old school building; Sasada has a favour to ask of Natsume.

Natsume finds a train ticket among Reiko's belongings and meets a hairy yokai named Santo, who is waiting for Reiko at the station; Natsume learns more about Reiko's feelings when he gives Santo his name back.

Natsume finds a town that had been submerged in water; Natsume gets possessed by a yokai and falls unconscious.