So you either like this series or you hate it. I don't think there is any middle ground on this one. While I'm not usually a big fan of the overly Moe series I will freely admit to loving this series and would absolutely recommend watching it, now if it would just get licensed for the states so that I can buy it and make all my friends suffer though repeated viewings of it.
What is K-on!? It's a fun loving never takes itself serious slice of life/musical anime series that follows a group of high school girls who join their school's lite music club. At first it's just Mio, a scaredy-cat bass player and Ritsu the leader and drummer who are a part of the group. Soon Yui a timid young girl joins the group thinking that she can join the group with her castanet playing skills but soon ends up being a guitarist even though she can't read sheet music or really even play the guitar. After a little bit Mugi joins the group as a keyboardist and while she comes from a wealthy family (provides for comic relief here and there) she is more interested in offering up tea and sweets much to the delight of the other girls. Their advisor is the music teacher Sawako who got blackmailed into her role as advisor to keep her Heavy Metal past in the past. She enjoys hanging out with the girls and is often finding ways to get the girls to cosplay. During the second year Yui's younger sister Ui, a much more mature girl than her sister, helps out occasionally and is a part of the gang but does not actually join the club. Her friend Azusa another guitarist and a first year student joins the club after watching the girls play. She is often perplexed by how the girls can be so good but practice so little. Yui nicknames her Azu-nyan after Sawako puts some cat ears on her head.
Toss all these girls together add fun adventures a sprinkle of yuri undertones and the occasional musical performance in and you have the ingredients for a very fun good time moe series. Oddly enough a lot of the Japanese Otakus were more in an uproar over all the rather expensive items that they could point out in series but that didn't keep them from creating a ton of fanservice material though. The first time I posted about how many images that were on Danbooru for Mio it was around 600 now it's standing at close to 1700 and still climbing. Images for K-on! in general is even more at almost 3000. That's a lot considering it's only been around as an anime since the beginning of April.
I've posted the ending song video before so this time I'm going to leave you with the opening song.
