Kwaidan: Stories and Studies of Strange Things (怪談 Kaidan?, also Kwaidan (archaic)), often shortened to Kwaidan ("ghost story"), is a book by Lafcadio Hearn that features several Japanese ghost stories and a brief non-fiction study on insects. It was later used as the basis for a movie called Kwaidan by Masaki Kobayashi in 1964.
Hearn declares in his introduction to the first edition of the book, which he wrote on January 20, 1904, shortly before his death, that most of these stories were translated from old Japanese texts. He also states that one of the stories – Yuki-onna – was told to him by a farmer in Musashi Province, and his was apparently the first record of it, both by his own account and according to the research of modern folklorists. Riki-Baka is based on a personal experience of Hearn's. While he does not declare it in his introduction, Hi-Mawari – among the final narratives in the volume – seems to be a recollection of an experience in his childhood (it is, setting itself apart from almost all the others, written in the first person and set in rural Wales).
In the last half of the book, Hearn presents collected Chinese/Japanese superstitions and his own personal thoughts on various members of the insect world.