Two completely different kinds of anime, from two very opposite sides of the coin.
Kara No Kyoukai:
Created By TYPE-MOON, famous for Tsukihime and Fate/Stay Night. Even the creator, Kinoko Nasu is famous for mixing his series so much that he has created a whole new universe of characters and symbolism, commonly called the Nasuverse. Think of him as the anime/manga equivalent of Hideo Kojima (of Metal Gear Solid fame), the amount of backstory for each character defies belief.
Kara No Kyoukai was written before the first real success from Tsukihime, originally a light novel before being given an anime 10 years later. I’m only giving this background to let you know why this anime should be given a watch, due to the intricate detail behind the scenes.
The main character Ryougi Shiki, without giving too much plot detail away, is a girl who had a taste for murder, and the Mystic Eyes of Death Perception, meaning that she can see lines across any object which only she can slice to kill that object, or as it was meant to be used on, people.
Suffice it to say, she uses it, and we follow a guy who gets attracted to her, Kokutou Mikiya, as they start to come across strange event as many murders happen in their town.
Shown in an anachronic fashion, much like the first season of Haruhi Suzumiya, so it starts off in the middle, giving you a confusing beginning episode, thinking you’ve missed something.
Sadly, it misses some of the details from the light novels, but overall, it maintains the feel and is a great story when you take it all in. There is a lot of exposition, so you need to be concentrating. Naturally, there is a large amount of blood, and one rape scene, not to mention fighting with bladed weapons, so not for the faint of heart or for the kids.
Animation is fluid, with a some good CG for the backgrounds. The soundtrack is one of the best I’ve ever heard, with strong strings and painfully sad piano tracks, with special choral tracks in the finale. 7 OVA only, but the episodes are long, and you will definitely want to rewatch your favourite scenes over and over again.
High marks from me if you want something deep to watch, with a decent plot that sucks you in.
K-ON:
Now, for the opposite, a happy, slice-of-life story of a group of schoolgirls who join the Light Music Club (though actually run it, since there’s no old members left), and just spend time together, mostly having tea and cakes.
Yes, a fairly brainless anime of how they begin to make music together, buy guitar for a new girl, going to beach to train, and even getting a younger student later who is a dab hand at the guitar.
Despite all this, the characters, whilst a bit clichéd (slightly ditzy rich keyboard player, the scatterbrained but fully likeable main character who plays guitar, one serious but easily frightened bass player, tomboyish girl on drums), mesh well together, and though it doesn’t go into more detail than the superficial (i.e., no deep problems with any person), with the cast as it is, you don’t need any more.
Honestly, you probably won’t rewatch the series once you’re done, maybe just the rare episode, but it’s a good for light viewing, and the comedy is good. You’ll get closer to the characters too, and actually begin to care about how they manage to play together.
Above average, depending on your preference. Don’t expect high class plot with hours of backstory (as with Kara No Kyoukai above, they have whole encyclopaedias for the Nasuverse!), and if you’re okay with an all girl cast talking about normal school days, then you’ll just relax and enjoy it. Good dose of melancholy for the olden days of being at school too.