My favorite girl and her character has such potential~
I can't really say that she has much potential, mostly for the way that she fades into the background. That said, her character development happens to be one of the most interesting in the series because you really get a look at the world around her and it's not quite as Hisako (or Erina, for that matter) thinks that it is.
However, because of that... she have become one of the many characters in SnS that I like. Not my favourite, but I like how far she has come.