Korea has short black hair, with a flyaway curl on the right side of his head. The curl is often drawn with a face in the middle, to represent his "Korean spirit". It is mentioned that he is significantly taller than both of his "brothers", and that he happens to be very muscular due to his experience in the military.
Korea is a free-spirited type, obsessed with video games, dramas, studying abroad, and the internet. He always claims credit for others' inventions, and feels that his older brothers should call him their older brother.
Though he is fundamentally serious and likes to put the family first, he can't keep his hands off his brothers.
It is said that he loves kimchi so much that he took it up into outer space, causing France to become ****ed off.
Korea has also been shown to be very good at drawing, as can be seen in a comic strip with China in which he tried to teach his older brother how to draw anime.
It is also shown that Korea is very bright seeing that he was able to create the Mind-Reading Binoculars perfectly when Japan failed to do so. But the same comic strip also reveals how clueless he is when he tries to use the binoculars to see what China was thinking of him, only devastated to see that China is glad that Korea took the stuffed animals because he didn't want them. Korea concluded that "Korea didn't make them" because he believed they didn't work.