Soem one knows Ayumi Hamasaki ?

Hi everyone!
You know, a few days ago, I think I was listening to the radio on the
windows media player..., The thing is that a girl caught my attention,
her voice and the song she was singing were beautiful, she´s called ¨Ayumi Hamasaki¨, so, I was wondering if some one coul tll me about her...
since then, I´ve downloaded some pictures and songs and Im starting to like her.
Is she from Japan?...