"East Sea" is not an arguable discussion, but it is a proved fact.

The name "Sea of Japan" has been decided in 1929 by internation hydrographic organization by the time when Korea was colonized by Japan. This is the only supportable reason that the sea between Japan and Korea is called the "Sea of Japan". However, historically, for 2000 years, the sea between Japan and Korea has been called "East Sea" by Korea, Japan, China, Russia, etc. Additionally, every naming method is currently in the view of continental origin. The sea between Japan and Korea is on the east side of the continent of Aisa since Japan is a country of island similarly to the United Kingdom located on the east side of Asia. Hence, the sea between Japan and Korea has to be called the "East Korea Sea" internationally by historical proofs and official naming rules.