"You know you're in for a ride when the anime you're about to watch has one of those retarded-long light novel titles involving a sister and way too many words to easily abbreviate. The marketing material calls it Nakaimo (like, say, Oreimo), but I like to call it There's a Sister Among Us. Or There's a sister. Or Who Is IMOUTO? Or any one of the other creative phrases floating on the internet. Or you can stick with the classic Kono Naka ni Hitori, Imouto ga Iru!"