According to your claim is ¡°Sea of Japan,¡± The One and Only Internationally Established Name, but It's just your argument.
Internationally accepted both name of " Japan of Sea", and " East sea" about the name of the sea between Korea and Japan. But only used "Sea of Japan" in your website.
As your wrong claim is General Worldwide Acceptance of the Name ¡°Sea of Japan¡±but the truth is not.
Japan insists that the United Nations has officially approved of the name Sea of Japan, which is not exactly true.
It is not the UN that uses the name Sea of Japan, but only its secretariat, a principal arm of the UN. Therefore, the secretariat using only the Sea of Japan does not represent the opinion of all members of the UN.
We have different opinions about the name of the sea that the two countries share, but I think it is best choice for now to use both " Sea of Japan", and " East sea" in consideration of international norms.