While not H, this has a nice picture of a naked Elly on the cover.
This is the book that laid out the original plan for the Xeno series story... before Squaresoft shafted the team. There are mech drawings, character sections, and more. I just wish I could read more than the 10% of the book that was translated by a now-defunct site.
Anyway, this book is part artbook, part character guide, and part Deus knows what.
This will not be a small download. The Doggie Bag version will clear 425 MB in size. For the rest of you, resampling is enabled.