East China Sea EEZ disputes
There are disputes between China, Japan, Taiwan and South Korea over the extent of their respective exclusive economic zones (EEZs) in the East China Sea. The dispute between the People's Republic of China (PRC) and Japan concerns the different application of the 1982 United Nations Convention on the Law of the Sea (UNCLOS), which both nations have ratified.
Source: Wikipedia — East China Sea EEZ disputes (CC BY-SA 4.0)