Diaoyutai is closer distance to Taiwan then to the mainland of Japan, other then Okinawa to Diaoyutai(equal distance to Taiwan-Diaoyutai)  Historically, polticially, treaty wise.. these Japs have zero advantage over China.

China should have repeat and do the same thing as these South Korean, suddenly drop 500 well armed and well trained PLA marines into the island, putting all ICBM on full alerts to target each and every Japan cities.

Lets see what so called Japanese advantage you talk about!