Gaijin Gyaru (foreigner gal) is a term used for Gyaru which do not reside in Japan, or in some cases it is meant to mean a gyaru who is not of asian descent. It is often a term used by gyaru in europe as well as other parts of the world to identify themselves.
There are some who find the term offensive, but it is generally considered an acceptable term by most gyaru for describing themselves or others, and it is not often used in a negative way.
Gaijin Gyaru have their own communities and groups dependant on country, and often host meetups and ocassionally events. There are a small number of gyaru circles in certain countries, although the popularity of actual gyaru circles vary between countries and communities.