My Theory:

There was once an anime with a character who had the name Hinata. Her personality was extremely shy, and yet strong inside. This idea was very popular amongst many artists and the general public, as it was viewed as cute and brought up many strong points about a persons character. Such as, do not judge a book by it's cover and the such.

This resulted in many recreations of that character. Nobody really wanted to change the look because it was cute and nobody could come up with a cuter look which fitted that personality so perfectly. Nobody wanted to change her personality, because it fitted the look so well and it was so popular amongst the Japanese General Public. Nobody wanted to change the name, because if you're going to use a character from other animes (with permission), you must keep the name the same or you will be editing the production, which is illegal unless the author allows it. But the author is afraid that editing the characters name, would destroy the spirit and origin of the character. Thus on legal issues, to keep the person the same, with the same personality, they are not allowed to change the name.

Even if the Author decided it was ok, it's best not to change it when everyone is so familiar with the character. Also, on an additional note, Japan is in the far east, and isn't it the place of the rising sun? (The sun rises and looks so beautiful when it does too), thus both representations of the name, in itself represents the people of Japan. "Sunny Place/In the Sun" both represent Japan very well due to the fact that Japan is mostly in the sun a lot of the time, and is a very sunny place.

This concept is very ironic amongst artists. Because the character that represents the Country, is very shy and yet so strong on the inside. The character is also very kind, supportive, but not very confident in themselves and rely on others to support her. Japan reflects this very well. It's kind of like a statement. Japan may seem small, and it may be isolated, but it is a strong country inside. The people are kind, and will support their allies with honour. They may also be stating something about the confidence of the people living in the country, or of the country as a whole. As to what that last one is, i'm not specifically sure.

The character, the name, and the look. Are all part of a bigger idea. A representation of Japan, the people, as well as being popular at the same time =P