Kotaku:"The Japanese language is different from the English language in a myriad of ways: it sounds different, the written characters are different, and the grammar is different. The sentence structure can lead to sticky or simply stinky translations, and the best translations are able to retain the nugget of the original, but still shine in English.
The cultures vary as well. It's not just the traditional bit, like the levels of politeness that exist in Japanese. It's also pop culture, points of reference, etc. So when video games are localized into English, it's not just a matter of going through games line-by-line and putting things in another lingo. Oh no, it's not that at all. Players need to be working from the same start point, and the easiest way to center them is through language. That's only the beginning."