This series was a huge part of the early history of 4chan and still appears to this day. It was at one time a series of comic strips by Azuma Kiyohiko that were eventualy published in collections and made into anime. It's about pretty much nothing other than the slightly (and I stress slightly) extraordinary lives of five (and other ancillary) high school girls. The series run ended 30 September 2002 (so I guess the last fansub was released 1 October 2002… coincidence?).

The main things you need to know (in order of ascending height): Chiyo, the small one. Tomo, the wild one. Kagura, the athletic one. Osaka, the autistic one. Yomi, the one that thinks she's fat. And finally Sakaki, the tall one that cats hate. Yes, cats hate her. You'd have to watch it to understand.

It's a nice little high-school series in which slightly amusing things happen. There's no magic or robots. It's very low key and fun.

As for why the freaks like it that has a lot to do with a couple minor characters. Firstly, Kaorin who has a seriously confused lesbian attraction to Sakaki (again this is low-key so it never goes anywhere and Sakaki shrugs it off, sadly). Secondly is the teacher named Kimura who has a weird attraction to his female students… I say weird with all seriousness, because it's not really acted on. He just says a lot of unfortunate things and tends to hang around PE. He is especially into Kaorin for the added twist.

There are any number of animated gifs where Osaka accidentally kicks off her shoe and causes some distant devastation. In the original, it just flew into the back of a truck and it was lost forever…

This text art that allows me to deftly avoid copyright infringement!