It's an amazing anime. People saying they don't like it are too small minded.
The art and music was amazing.
Yes the anime is pretty much all female characters.
There are lesbian undertones but that isn't made the main focus of the show at all.
This being an almost all female character anime, it leaves room for very cool, abstract female characters that you don't usually see in other anime.
I think the crazy, psychotic, matriarchal themes of this show is just so beautiful and nostalgic for me as I went to an all girl's school.
The representation of female psychopathy amongst other females in a matriarchal set up was really cool.
I would say the only con is the cheap oversexualization sometimes due to the creators of this show being male.
But if you can look past that it is a very fun, entertaining anime that has a lot to offer.
The fact there is no "plot" as said by some makes the show better. It makes you feel like you're part of the school.
It's great I loved it.