WARNING POSSIBLE SPOILERS
Bakemonogatari is part of the Monogatari series of light novels that has been turned into a anime series.
The basic premise is about Koyomi Araragi, whom saves Hitagi SenjÅgahara from a fall, he realises she weighs almost nothing and offers her help to bring back her weight. This then sends him down a path to help others or their spiritual plights. Coincidentally they all seem to be women he ends up helping so there is that constant 'hareem' factor in it. Despite this, there is very little fanservice but a large amount of innuendo.
It has so much charm, personality and character than anything else I have seen in a long time. I would like to say there is main character but I would be more correct in saying there are more lesser
albeit main characters as well. The show centers around a group of people, in Highschool and Junior high. Araragi Koyomi and Hitagi SenjÅgahara could be called the main character's of the show - it would be fair to call them the main progression of the show. Suruga Kanbaru, Mayoi Hachikuji, Tsubasa Hanekawa and Oshino Meme and Shinobu are all other characters that play a vital part to press the story. The series is broken up into varying "scenarios" involving these characters, where they are all intertwined.
If you do end up watching it you may be a bit lost as to why some events have occurred prior to the initial series, and you are just given glimpses of what has transpired prior to Bakemonogatari fear not the show does not follow chronologically but the following series do fill in the gaps that you thought you may have missed. I really believe that it wouldn't have worked any other way, it's really like a story being told in fragments so everything comes together in the end.