Korea is older.

That's it.

BUT Korea is definitely NOT older than China. We all know China is one of the oldest countries out there.

Korea copied China and then Japan copied Korea.

Pretty much lol...when things first got started I mean.

But if we want to get more complicated.

Is Korea...

The Korea of Three Kingdoms.

Or

대한민국 (South Korea)

Well I like to think of it as like the Italian brothers kinda

North and South Korea. Both agreed on the same things. They were one. But after the war, they split. South keeping the southern and North keeping the northern part.

Random fun fact: Korea does have different dialects depending on where you are. Kinda like the North and South in the USA.

Either way, Korea is older than Japan.