See, the two posts above are why this all exists. IE10 and 11 are not crap - actually, for the end user they're just as good as the others these days. Unfortunately, we all think of IE and instantly think IE6 and the bad old days.
Those days are gone. This ad and everything around it is Microsoft trying to point out that IE isn't as awful as everyone on the internet seems bent on believing. And this is why the whole ad campaign is aimed squarely not only at East Asia, but at the internet in general. It's a sure bet that "IE-tan" will get our attention, and some of us might stop complaining for long enough to watch the video.
It's a good play. And, oddly enough, a surprisingly competent magical girl short while it's there. Will it convince anyone that IE stopped being a slow, buggy, and incompatible browser several years ago? I doubt it, no-one is listening. But it's the best Microsoft can do.