Actually most anime characters look asian, mainly in the fact that most of them, especially the women characters, have faces with not that much definition but more with large cheekbones and a sharp chin. Just like an asian.
Their eyes also have a large seperation which is obviously exaggerated however, asian people do in fact have a larger seperation of the eyes than white people due to the fact that their noses are generlly wider, but also smaller in terms of depth. (lack of cartalige) This make their noses seem smaller by comparison. Also, anime eyes tend to just stick out, this also is an asian trait since asian people don't have depth to their eyes, their eyes, pertrude from the face more whereas, white people have eyes that are more "sunken in".
Obviously not all anime characters have these traits, for example, I personally believe most Final Fantasy characters have a mixture of caucasian and asian in them, and it is different for each character. For example, : Yuna FFX = 70% asian, 30% caucasion. Lightning FFXIII = 75% caucasian 25% asian. These are just my own opinions and examples but you get the picture. In fact FF artist Tetsuya Nomura even explained when talking about characters like Cloud FFVII, that he was designed to look like white guy. So like I said not all of them are asian, some have a caucasion mix.