The Japan Times says Japan is preparing for attack by China:
The Defense Agency has prepared a plan to defend the southern remote islands off Kyushu and Okinawa from possible invasion amid rising security concerns about China, according to documents obtained Saturday by Kyodo News.
The agency compiled the plan in November on the assumption of an invasion of the islands located within a 1,000-km zone between the southern end of Kyushu and Taiwan.
Thousands of islands are scattered in the area. The Senkaku Islands, claimed by both Japan and China, are among them.
The plan calls for a dispatch of 55,000 troops from the Ground Self-Defense Force as well as planes, warships and submarines from the main islands in the event the remote islands are attacked.
“China has been expanding its scope of activities as seen in the case of an incursion of Japanese territorial waters (by a Chinese nuclear submarine) in November. We need to monitor its moves,” the official said.
In September, the agency presented scenarios of Chinese invasions of Japan. A report listed possible attack scenarios by China, including a territorial dispute over the Senkaku Islands and illegal operations by Beijing over maritime resources in the East China Sea.
The Ground Staff Office of the GSDF previously drafted a plan to cope with cross-strait military conflicts between China and Taiwan. But the new defense plan is the first penned by the agency on the assumption of an invasion of the southern remote islands.
I found this article via this, but the page has dissapeared. He noted that it was extremely odd for this information to be leaked and was wondering what was really going on.