The name East Sea has been in use for 2,000 years

Samguksagi (History of the Three Kingdoms) recounts the history of ancient states in Korea and the name "East Sea" was used when describing historical events that occurred around B.C. 50.

The body of water that Koreans have called the East Sea (??Donghae?? in Korean) for the past 2,000 years is widely known as the Sea of Japan to many other countries. But, as indicated in the book Samguksagi (History of the Three Kingdoms, 1145), the first known use of the name East Sea was in 37 B.C., predating the national name Japan by some 700 years. "Japan" was first put into official use in the 8th century.

"Simplified Map of Japan's Periphery" drawn by Takahashi Kageyasu, a well-known Japanese cartographer, describes the sea area located to the east of the Korean Peninsula as the "Sea of Joseon" (name of the last Korean dynasty).

The name Sea of Japan has stood mainly because during the early 20th century when the work of setting standard geographical names was in progress, Korea was unable to participate in the decision-making process since it was under the Japanese colonial rule. Japan??s seizure of the Korean sovereignty and its rising international status at that time greatly influenced the mindset of the mapmakers of the Western world.

It's wrong to name a sea after a single country, so simultaneous use of both names is appropriate

Since the sea itself is bordered by four countries (South and North Koreas, Japan and Russia), there is a clear need to agree on a name that is acceptable to the neighboring nations. If the nations involved fail to arrive at a consensus, it is recommended that both names appear concurrently. In the case of conflicts over geographical names, the UN conference on the Standardization of Geographical Names recommends concurrent use of both names for the time being.

Geographical Stance

Furthermore, it has long been a general practice to decide on maritime geographical names based on names of continents located on the left side. Korea's claim is that East Sea identifies it as the sea to the east of the Eurasian continent, not only the Korean Peninsula