In a word: Random.
If I had to add another word, it would be: Hilarious!
Forgoing my usual review style, because this anime defies normal. It's not really a story, per se, as it is a series of shorts that are, for lack of a better word, random. Most are fairly hilarious(sometimes epically so!), or at least funny, although a few just seem to make you go "...what was the point of that?" I'll admit, sometimes the jokes would probably have worked better with a native Japanese speaker, as they relied on puns or at least culture significance, but there was still much in each episde that had me laughing hard.
Primarily, it follows three school girls, and their zany antics. But there is such an array of other characters, that it is hard, if not impossible, to adequately describe them or their role in the series. Everyone has a quirk, but it's watching those quirks play off each other, that provides most of the hilarity. Even the girls seem aware of their quirks, and delve into them with gusto.
So, gonna end this short review by saying this is a must watch, if you want something to laugh at. Not only are the characters and situations hilarious and/or wierd, but there is an endearing quality to them (especially Nano and the Professor), that really makes you feel for them.