There are many reasons we should call 'East Sea' instead of 'Sea of Japan'.
First, 'East Sea' is the name that was used for a long time. It has been used in Korea for over 2,000 years. When we look at the old maps that were used in East Asian countries, the sea is written as 'East Sea' not 'Sea of Japan'. But no Japanese record published up to the late-18th century indicated any name for the body of water.
Secondly, according to the International Hydrographic Organization, ¡®marking at the same time¡¯ is recommended if the parties fail to agree on a single name for the terrain they share. Therefore, I think that the sea between Korea and Japan should be described as the ¡°East Sea¡± or at least with the simultaneous use of both names; ¡°East Sea/Sea of Japan.¡±
Therefore, I would like to ask you to change the maps that wrote 'East Sea' as 'Sea of Japan' into the ones that wrote 'East Sea' correctly.