So in case you've never watched K-on here's a summary:
K-on is about 5 girls that start a rock band in an all girls school. Together they grow up and enjoy high school together.
K-on is gifed a lot so you may have seen it, believe me it as good as it looks.
The plot for K-on isn't amazing, and I'm saying this as a hardcore K-on fan. What makes K-on so special is its soundtrack and characters. It brings a whole new light to rock. The band (Houkage tea time) makes, no creates adorable/catchy music without breaking the rules of rock. The characters are crazy cute and get along very well demonstrating the usual high school best friends. The art is good not great and the animations are average.I enjoyed this anime a lot but it's not for everyone.