The cuteness, omg.
The STORY of Yuru Yuri is a plain and simple one that follows the lives of middle school girls as they go about during they day-to-day lives. There is really not much in the form of story that could make this anime exciting because this is very much a character-based series.
The ANIMATION was... perfectly fine? There wasn't anything that made it stand out from other animes, to be honest. It's cute, to be sure, but that's about all it has going for it.
The SOUND might be a hit-or-miss for people. I've read some reviews that hated the OP, but I LOVED it. At first, I thought it was really annoying, but as I continued watching the series, I couldn't help but start singing along and bobbing my head. It's very catchy. The seiyuus also did a wonderful job and each character's voice matched perfectly to their personalities.
Okay... CHARACTERS. This is what made Yuru Yuri fantastic for me! I really loved all of them, but I especially loved Yui. She is so calm and collected and cool. Of course, it's Kyoko who the show really revolves around, mostly because the writers probably wanted it this way, but also because her personality is very domineering and over-the-top. I also enjoyed the on-going pranks with Akarin being invisible and having no presence. You can't help but feel sorry for her while you're laughing at her.
I did not like the sexual harrassment with Akarin, though, and I need to put that out there. It's not cool and it's never funny and I hate when anime try and make it okay.
OVERALL, this is a show for laughs. There's not much seriousness that happens in the show, but that's okay! It's not a serious show and if you're looking for something mellow and contemplative, skip this. If you're looking for some light-hearted fun with some girl-love on the side and slapstick humor, then give this one a whirl.