The book is a collection of short stories by Yamashiro Asako, set in Edo period and connected by the protagonist who is traveling Japan’s onsens, where she hears or encounters all those mysteries. The two stories Ishida recommended are these:
“The Lapis Lazuli Illusion” – an embryo commits suicide in the womb to break its reincarnation cycle and descends into hell.
“Hell” – a person gets ambushed and imprisoned by bandits and is forced to eat human flesh to survive.