Why do some idols have two names?

JAV Idol Club · 2011-08-13

I recently discovered that Ayaka Misora is Ameri Ichinose. Why does the same person have two stage names?Did Ayaka change her name to Ameri recently?maria ozawa as known as Miyabi..i dont know for sure.I think it has to do with working for different labels or wanting to do a different kind of video.bigjoey is right, transfering to another agent company is one of many reasons.And changing name being believed could improve lucks in actress's career.nice answers, now I know why