Lovely Sweet Dream is a published version of O.S.D. employee Hiroko Nishikawa's dream journal.
The journal was kept over a period of years, and served as inspiration for LSD: Dream Emulator. During development of the game, a variety of artists were called upon to provide illustrations for each dream entry in the journal. The final product of this effort was Lovely Sweet Dream, which was released alongside LSD.
Most dreams are accompanied by an English translation, but there are several pages in the book which contain only Japanese text.