Natsume's Book of Friends volume 7 features story and art by Yuki Midorikawa.

Someone is attacking yokai and stealing their blood, and Takashi is dismayed to discover that the assailant is human! The more he investigates the attacks, the more danger he finds himself in as he digs deeper into the occult world of the exorcists. Someone is planning something horrible, and even the help of Natori - actor and exorcist extraordinaire - might not be enough to save the yokai... or Takashi!