We say the name how it is presented to us. It is the Koreans who choose to go by their last names first. The Vietnamese, on the other hand typically give us first middle last, like Ke Huy Quan, who's name in Vietnamese is Quan Ke Huy. Most Koreans I went to school with used their last name as a first name. That's apparently how they filled out their paperwork. Idk why. When Chan Ho Park came to the US to pitch in MLB, he said he wanted to be called Chan Ho Park, not Park Chan Ho. It was confusing.