I remember about a year or so ago I found this awesome video on Youtube. It was animated by the uploader in an anime style of drawing. It was this love story about a boy and a girl that are separated by this transparent wall. They can't hear each other, but they communicate by writing messages and drawing on the wall. Eventually, they begin to like each other and want to be with the other one, but they can't. So the boy tries to smash into the wall, but to no avail.
I can't be sure about this, but I think in the end the boy gets a gift from the girl, and it turns out to be her arm? I'm really not sure as it's been a long time.
If anybody can help me find this video, I'd be grateful.