The term "Asian plastic surgeon" is used to denote a doctor skilled at performing the highly specialized cosmetic procedures tailored to the Asian body and not as a reference to a surgeon's personal genetics, ethnicity, or location of practice.
Whether a surgeon was born, trained, or works in Korea, Japan, China, the U.S., or Canada is not that important in determining his or her level of skill. The most accomplished surgeons for a given operation may be of Asian or non-Asian descent and are just as likely practice in Los Angeles as Seoul.
While every patient would like to believe that his or her surgeon is the "best," no organization can designate one or two surgeons to be the finest in any field of surgery, and no country or geographic region can claim a monopoly on the most talented practitioners.
Even if the title of "world's best Asian plastic surgeon" could somehow be bestowed, it would at most refer only to a single operation (for instance, double eyelid surgery) and not every conceivable cosmetic surgery performed head to toe.
So since the "ultimate" plastic surgeon can't be determined, a patient researching possible doctors will generally do better limiting his or her search to within a group of top specialists for Asians who fufill certain criteria known to be associated with a high degree of competence.
What criteria might these be? To the right are a number of links to short essays that may help you locate the best Asian plastic surgeons for your individual situation and needs.