Do the Yami Shibai horror stories have any background/reference?
ANN writes the following:


  A series of short horror stories based around Japanese myths and urban legends. The series is framed around an old man telling these tales to schoolchildren on a playground using kamishibai, a traditional Japanese storytelling method using paper scrolls.


The same goes for summaries on crunchyroll or other sites.

I guess that stories like "Hair" (the photocopier-one) are just urban-legends, so there isn't much to explain.