This link takes you to a scanned version of the 202-paged biographical dream journal by Hiroko Nishikawa, an artist at Asmik Ace Entertainment who had been keeping it for a decade.

http://dreamemulator.wikia.com/wiki/The_Dream_Journal

The game is loosely based around the journal; for example in terms of events and dynamic objects that can be encountered corresponding to a reference in a journal entry.