Not sure if you know any yet, but here goes:
Gackt - Brilliant musician who first became famous as singer of the band Malice Mizer in the late '90’s and later started a great solo career. His very first band was called Cains:Feel, but they broke up after only a demo. However, as a solo artist he is still around.
Gackt and Hyde also both played in the movie Moon Child, which was written by Gackt.
Onitsuka Chihiro - First discovered her on the OST of The Novelist and Mood Indigo
One OK Rock