You used the word 'sea of Japan', not a 'East sea'. Actually, Sea of Japan is not a correct word. The term “East Sea” has a deep relationship with the history of the International Hydrographic Organization. In order for the world’s seas to have standard international titles and ensure safe voyaging, the International Hydrographic Organization or IHO establishes these much needed international standards.In 1929, the IHO published a book titled “Limits of Oceans and Seas” in which the world’s oceans names were internationally standardized.

The “Sea of Japan” name began being widely used internationally from the release of the 1929 IHO released “Limits of Oceans and Seas”.

At that time, Korea was under Japanese occupation and thus could not participate in the publication process. Therefore, it unilaterally reflects Japan’s position in the international community.