#51 of Atomic Bunko/Atomic Pocketnovels, this is sort of ero-fantasy comedy with a harem ending. Not my scan, same cropping problem, unable to joint the color illustration but managed to joint the character page.
info on mugi: http://doujinshi.mugimugi.org/book/598371/
digital ver: http://www.dlsite.com/books/work/=/product_id/BJ021576.html/