Hong Kong, a former British colony, has been one of China's special administrative regions since the 1997 handover.
More than 90% of residents are ethnic Chinese, and the territories have very close ties, but there's no open door. Chinese that live on the mainland must apply to visit or relocate to Hong Kong.
The economies are tightly linked, and many of China's rich are likely attracted to the freewheeling brand of capitalism practiced in Hong Kong.
Beijing billionaires may find the language difficult, however. Cantonese is spoken in Hong Kong, while Mandarin dialects are popular in northern China.
