I completely agree with Roger64.
I can't believe Japan is now trying to even dispute Chunxiao gas field which lies on the side of Chinese EEZ.
It seems it is a trend that Japan always trying to invade China or Korea. Historically, there is never a "China problem" for Japan where as Japan is ALWAYS a problem for China. Japan has historically benefited from China (technologies, religion, resources) while China has rarely been benefited from Japan. Japan had historically invaded China and Korea numerous times in the past - not even counting the times where Japanese pirates raided coastal area of Korea and China. While China never try to invade Japan once.
It seems Japanese are becoming more and more assertive now, they are already almost forgetting their WWII past. Every year, it seems the support to abandon article 9 is becoming stronger and stronger. Its only matter of time (maybe in less than a decade) when they will finally pass (they have already propose to abandon Article 9 numerous times in the past). They also upgraded their "defense agency" into a full "Ministry of Defense" just few years ago,while seeking to aggressively expanding their power projection capabilities (Hyūga class helicopter destroyers - which are helicopter carriers but in reality can easily be used as normal aircraft carriers when F-35s are sold to Japan), it won't be long they will start another war with China - sadly this time, at the delight and probably full support of American and their allies.
And I agree with Roger, Japan has little resources. For example - rare earth minerals, oil, gas, nuclear fuels, arable land. It cannot be self-sufficient no matter how much they try - and as year goes on, technological society requires enormous resources to sustain itself - especially for a high tech country like Japan. This will definitely be the driving factor for a new militarized Japan no matter how much they try to say they will never wage another war.
Its not because China wants a war with Japan, its because Japan wants to have a war with China (and eventually rest of Asia).