Similar setting, story and characters. If you enjoyed Manabi Straight, then i can guarantee you'll enjoy K-ON!
Manabi = Ritsu, Mika = Yui ,Mei = Mio, Momo = Tsumugi
The humor and Slice of Life elements are quite smilar.
Both are trying to bring back a club in Manabi straight its the Student Council and K-ON! it's well, the K-ON! club!
Manabi is set in the very slightly not so distant future, where a slice of life anime takes place involving girls in a club not doing a whole lot but still managing to make a great, cute, adorable, anime. Manabi is K-on minus the music. Momo is Mugi, Manabi is Yui, Mika is Mio, Mei is Azusa, Mucchii is Ritsu
All right, how do I begin...They're both about cute girls who attempt to save some sort of activity (in Manabi's case, the student council) through believing in themselves and inspiring moments, against some sort of odds. Most of the cast of Manabi have K-ON! counterparts that are unmistakable, and really, the overall feel made me rename K-ON! "Manabi Straight With Guitars". So, if you like K-ON!, there is absolutely no reason why you won't like Manabi.
Cute little girls dealing with their problems in a school club, that's what we want!
Both shows feature similarly shallow "moe" archetype schoolgirl characters, their daily life in a school club and how they work to accomplish a goal together.
Both are about a group of girls doing things in school.
However, Manabi Straight has an actual plot and a strangely satisfying ending. Also, the setting is more interesting. In any case, dont watch K-On if you expect any kind of plot like in Manabi straight, because there is none.
K-ON! and Manabi are both about five girls who are in a club together (the Light Music club and Student Council respectively). Even though K-ON! seems to be a lot more popular, I personally consider Manabi to be a lot better.
"Don't stop, keep trying." A quote used from the main characters that gives up on something where is about to shut down, but manage to get people's attention and gained it's popularity. There are characters that are quite similar in here: Ritsu = Manabi, Mio = Mei, Yui = Mikan etc. There are some funny and cute moments from time to time.
The difference is that Manabi Straight is set in a near future like setting, a balance of comedy-drama story, and focuses on the student council activities. K-on focuses on music, the present day, much more comedy and focuses on club activities.