Today's free book is
Legend in Japanese Art: a description of historical episodes, legendary characters, folk-lore, myths, religious symbolism, illustrated in the arts of old Japan by Henri L. Joly.
This is an astounding encyclopedia, organized alphabetically. It does not give full versions of the stories, just brief summaries — but it is an excellent reference work. The book is available at
Hathi Trust and at the
Internet Archive.
I have embedded the Internet Archive edition here so you can see how the encyclopedia part of the book is set up: