When Natsume and his friend Tanuma help a young woman find her way through the woods, they end up having to take cover from a storm in a mysterious mansion! The shelter comes at a cost though, and the boys are cajoled into joining a séance to summon a yokai. But when a sudden power outage disrupts the ritual, Natsume, Tanuma, and Nyanko Sensei are faced with something far more strange than the errant yokai they were expecting!

Volume 29 of the Natsume's Book of Friends manga series by Yuki Midorikawa.