I was already aware that Arabs don’t like to refer to the Persian Gulf as the Persian Gulf. They prefer to call it the Arabian Gulf, although the rest of the world ignores their preference. Some lawmakers in New Jersey are representing South Korean interests and trying to get the state to refer to the Sea of Japan as the “East Sea.” If the bill is adopted, textbooks in the Garden State would have to reflect the change by 2016.
Maybe the answer here is not to refer to bodies of water as somehow belonging to any particular country or ethnicity. No one complains about the Atlantic, Pacific, Southern (Antarctic), or Arctic oceans, but I imagine some people might not like the designation of the Indian Ocean.
In any case, no one cares what New Jersey thinks about the Sea of Japan.