It is a black youkai that following Natsume.
Appearance[]
It resemble the Mieri urban legend.
Plot[]
At first, the black shadow was seen by the roadside, seemingly waiting for something. However, the next day, it was confirmed to be following Natsume since it had arrived at the front gate of the Fujiwara's fammily. When Natsume took off to school, he tried his best to avoid the black shadow by the front gate.
Later that day, after Natsume returned from school, the black shadow had moved closer to the Fujiwara house and now at the front door.