It's a story about Himawari-san (so called because she runs a small specialty book store named Himawari, right next to a school) and a school girl named Matsuri. Matsuri is drawn to Himawari-san for some reason. I can kind of understand it because Himawari-san is pretty and cool. Frankly, though, I wouldn't classify this book as yuri at all. It's just an oddball manga with slow but heart-warming plot. I'd have preferred a story focused more on Himawari-san & Matsuri, instead of bringing in all sorts of other weird and distracting characters into the story.
I like the art work enough to mostly look past its shortcomings, though.