Japanese ghost stories?

Question:

Is it kaidan or kwaidan? Because I thought it was kaidan but I have a book of ghost stories and it says kwaidan on the cover. It's kaidan right?

Answer:

Yes, kaidan is correct.
But it's funny that kwaidan sounds more horrible and suited for a title of ghost stories.
Kwaidan seems to be a coined word by combining kai (mysterious of suspicious) and kowai (scaring) and dan (story). I think the person who wrote the title did so on purpose. He/she must have a good sense of Japanese, I bet.