We have opposing opinion when it comes to a common name to be internationally used for the sea between the Korea and the Japan. Considering that the two countries are using completely different names and that it is unreasonable to adopt only one of such names, specifically the name "Mar de Japo'n" in this case, South Korea advocates the concurrent use of both names the "Mar del Este" and the "Mar de Japo'n." However, Japan finds it unacceptable to take on any other name except the Mar de Japo'n, insisting that it has already been internationally established.
Taking into account the geographical traits of the waters, the international norms for establishing geographical names and the historical legitimacy the name East Sea holds, South Korea considers it proper to use both names used by each country while the two countries remain in disagreement on a common name for the sea they share.
The sea in question comprises an Exclusive Economic Zone and the territorial waters of four countries: South Korea, North Korea, Japan and Russia. As such, adopting a single designation named after the name of a specific country cannot be justified for waters shared by multiple countries and influenced by each of their sovereign authority.
Naming a geographical area shared by two or more countries is usually determined by an agreement between the countries involved. If an agreement cannot be reached, the general rule of international cartography is to concurrently notate each name individually endorsed by different countries involved. This rule is also confirmed through resolutions of the United Nations Conferences on the Standardization of Geographical Names and the International Hydrographic Organization .