It pulls us in, it’s exciting, it’s something mysterious and they have many names such as, ghosts, spirits, hollows…. well the list can go on and on with all the different names. Kyoukai no Rinne is one of those anime and the spirit concept is something anime deals with regularly.
Sometimes it can be in terms of energy from characters who have died but project some part of their energy in the main protagonist. At other times, we have full blown spirits/ghosts that are lost or just want to reek havoc upon the world. Usually, the spirit concept is just a small plot in a larger story.