It's hard to say for sure. 'Tar' could be a completely fictional creation or it might draw inspiration from real-life situations and then be embellished.
Well, it could be. But often, even if inspired by real life, movies or books might tweak things for dramatic effect or to make the story more engaging. We'd need more info on 'Tar' to know for certain.
Tar fiction is not a commonly known term. Maybe it refers to some fictional works related to tar or something made up using the word 'tar' in a creative context. I'm not really sure though.
I don't think so. Tar is not typically associated with a ghost story. It's more likely to refer to a substance or something else unrelated to the supernatural.
The unique concept of a demon lord having to work in the human world is really appealing. It combines the elements of fantasy and the daily life in a very interesting way.