A simple auction takes a turn for the sinister when the entire venue is locked down after several priceless items go missing. To make matters worse, the human guests aren't the only ones stuck in the mansion! Now Natsume, his friends, and his questionable allies will need to solve the mystery of the thefts and uncover the secrets of the Nakatomi manor if they ever want to get out.

Volume 31 of the Natsume's Book of Friends manga series by Yuki Midorikawa.