Unless I'm missing something here, what about one of the videos on the internet that have the full audio? That solves the entire translation question right there, doesn't it? (I'm not trying ot be know-it-all-ish or my-way-is-right or anything, I'm just wondering why not use a vid with full audio.)
http://www.wat.tv/video/ayumi-hamasa...ori_ltoa_.html