I have no idea at this point whether or not this report is credible:

“Q: There are reports that Japan’s Ground Self-Defence Force recently deployed surface-to-ship missiles (SSM) in Okinawa’s Miyako Island, and plans to deploy SSMs in Kumamoto Prefecture in 2016. Some media reports believe that these moves are meant to deal with China’s possible attack against Japan’s southwest outlying islands. What is China’s response to that?

A: Japan’s moves in the military and security fields will have complex impacts on the regional security environment. Therefore, Japan should give responsible statements as to its true intentions behind these moves. China adheres to the diplomatic principle of good-neighborliness and friendliness and the national defense policy that is defensive in nature. In the meantime, we will take firm and effective actions to respond to changes in the security landscape and safeguard our national territorial sovereignty.”

http://www.fmprc.gov.cn/mfa_eng/xwfw_665399/s2510_665401/t1165908.shtml