NATSUHIME is the successor to the now defunct GELATIN Magazine, offering basically exactly the same thing but with more nudity and racy comics. Judging from this first volume, it seems like it's going to head even more in that direction; half of the comics feel like they were intended for the June issue of GELATIN that was canceled at the last minute, and just don't fit the new more adult theme.
Kuroboshi Kouhaku is probably best known as the illustrator for Kino's Journey, although he's worked on numerous other games and series like Summon Night, and Allison & Lillia. And while Kuroboshi Kouhaku hasn't participated much in the doujinshi scene, he has released a few gems and Granada Level Q has to be the best of them.