The site named ¡®Sea of Japan¡¯ instead of ¡®East Sea¡¯. Actually, a conflict between ¡®Sea of japan¡¯ and ¡®East Sea¡¯ still exists and it¡¯s not over, so it is the best option to use two names together until the two countries agree on the common designation of the UN and the International Hydrographic Organization.
It is not fair to confine the ocean surrounded by many countries in the name of a country.
So, In the case of Sea of Japan, I would recommend you to change the name to ¡®East Sea¡¯ or emblemize both ¡®Sea of Japan¡¯ and East Sea¡¯.