The sea between the Korean Peninsula and the Japanese Archipelago is mainly called “Sea of Japan” in the international society. Concerning this, two Koreas have raised complaint under the rationale of the historical background and the international norms. The complaint of the Korean people concerning the naming issue most deeply lies in the fact that the name “Sea of Japan” which is “favorable” to Japan has been used as the (sole) official international name, whereas the name “East Sea” which is “favorable” to Korea has not been adopted even as the second official international name, regardless of its exact historical background. In the naming dispute like this, the best solution is to create a neutral single name through negotiations by the countries concerned. In case the countries concerned fail to create a neutral single name, the second-best solution is to use multiple names. From this kind of viewpoint, concerning the naming dispute, this article requests three countries, Japan, South Korea and North Korea, to negotiate to create a neutral single name.