Chapter 18, titled Do Not Call Last Part (第十八話 呼んではならぬ 後編, Daijuuhachiwa Yonde wa naranu Kouhen), is the eighteenth chapter of the Natsume's Book of Friends manga series. It is the second and last part of the two-parter arc, "Do Not Call."
In Japan, it was first published in Hakusensha's shojo manga magazine LaLa in September 22, 2007 (LaLa November 2007 issue #397, No. 11).
Tooru Taki is a girl of Takashi Natsume's school who got cursed by a youkai because of a spell circle she inherited from her grandfather that let her see youkai as long as they are inside it. Trying to help her, Natsume himself got cursed and then captured by the youkai. He's able to escape, but not before the youkai remove his ability to see youkai temporarily. Now on the same level as Taki, the both of them and Nyanko-sensei have to find a way to win against the youkai without being able to see them.
Yuki Midorikawa's afterwords illustration of Chapters 17-18.
"I had a lot of fun working on this one. Strange how having a girl in the story makes things go so smoothly for me. I was working on this story at the same time as Chapter 19 (which I was submitting forLaLa DX) so I had the most work I've ever had at one time. I wished I had had more pages to work things out, but overall, it was a positive experience. The story evolved from the ideas I had of big graffiti, and the concept of being able to see yokai conditionally. Natsume was never able to meet his grandmother, but Taki was good friends with her grandfather. They had different relationships, but sometimes that allows for better perspectives. I also had fun drawing a frightened Nyanko-sensei."