Hmm, interestingly it got Kamio Misuzu from Air. Though in my opinion, there weren't nearly enough questions asked to actually get it down to any sort of specificity. Pretty much it somehow sorted it from blond female anime characters that wear school uniforms and doesn't have siblings. Failed on Minagi from the same series, though the questions for that are really hard considering her story.
Part of it though is luck, since the questions it asks are sort of random. I have definitely seen questions that would have easily narrowed down the answer in other tries, but the computer ends up wasting its questions on not very useful stuff. The way to trick it is to find someone similar to a famous character because the way the algorithm works. The same principle holds for niche genres. If your character is representative of something, chances are he will get it, which is probably why he got Misuzu.