The Ministry of Foreign Affairs has announced its intention to grant multiple entry three year visas to Chinese visitors to Okinawa. Tourists can make as many visits as they want, provided each visit is no longer than 90 days. Not sure how immigration would view someone who ended up shuttling between the two countries, spending most of the time in Japan. Until now, individual visitor visas for Chinese are for a maximum stay of 15 days. Although the plan is focused on Okinawa, tourists will be able to visit other parts of Japan. Other prefectures have asked for more flexibility over visas but MOFA selected Okinawa as most in need of the potential economic boost. It may well be the first port of entry specific visa offered by Japan.
Source (Japanese)