Not a single book, but six separate ones, tucked into a clear plastic folder that keeps them together and protects them. One book for each girl in the game (Aya, Nayuki, Mai, Makoto, and Shiori) and one book for the game itself. Each book for the girls is full of illustrations and screen caps, including some adult pictures (naughty bits are blurred out), sketches, and a poster. Very nice collection!