Takashi Natsume, the shy youkai specialist and master of the Book of Friends, continues his road towards self-acceptance with the support of new and old friends. His most essential ally is still his gluttonous and sake-obsessed guardian, the haughty but ferociously protective wolf spirit Madara—or Nyanko-sensei, as Madara is known when he is dressed as an ordinary, fat cat. Natsume is attacked and kidnapped by a weird bunch of masked, monkey-like youkai, who have taken him away to their forest while feverishly searching for the Book of Friends. When Nyanko-sensei realizes that his "servant" has been kidnapped from under his nose, he enlists the assistance of Natsume's youkai companions and undertakes a rescue effort.