According to international organization, "If each of two or more countries use different name, international organization advises the name's simplification, and if it can't do, if has to use both names."
For instance, in the most widely read encyclopedia in the world, The Encyclopaedia Britannica, states the sea both the "East Sea" and "Sea of Japan."
I humbly ask for you to consider the issue of naming the sea both the "East Sea" and "Sea of Japan."
Thank you for your help, and I look forward to hearing from you via my email : yjkwon0079@gmail.com.
Yours sincerely,
Yongjoon Kwon