http://www.youtube.com/v/3dWyWX7y3XoSynopsis (from MAL)
The school romantic comedy revolves around a second-year high school student named Sorata Kanda who lives in Sakurasou, the dormitory for problem children at Sorata's school. One day, Mashiro Shiina ?a cute girl who happens to be also a cosmopolitan, brilliant artist? moves into Sakurasou.
Sorata thinks to himself that he should protect Mashiro from the weirdos at Sakurasou, but Mashiro has a surprising secret: she has no idea how to take care of herself. She gets lost if she goes out, and her room is a complete mess. Sorata's dorm mates designate him as the "master" of Mashiro, and thus, an ordinary boy and a brilliant girl must live like "a master and his pet."
What the synopsis leaves out is that the reason Sorata ended up living in Sakurasou is that he couldn't resist taking in stray cats, which was against the rules of the dorm he was living in. That is what makes him a "problem child". The others in Sakurasou? Hard to say, but they are bound to be eccentric! Also, the dorm mother, or whatever you call the adult in charge, is Shiina's aunt. She pretty much sets Sorata up, expecting his tendency to help strays will kick in when he meets the totally brilliant, but befuddled beauty that is her niece. (Conveniently relieving her of the responsibility of caring for her!)
I read the first few chapters of the manga adaptation of this, and it looks very funny, if a bit predictable. I am looking forward to it!