Okinawa
Okinawa is a place I can truly call home. I have lived here longer than any other country -- a total of 13 years. It is a part of an island chain called the "Ryukyu Islands" off the coast of Japan. It is surrounded by beautiful beaches and wildlife. Many of the locals will understand some English, but it is always nice to learn the greetings and how to say "Thank You" or "Excuse Me". Head south to get a taste of the city life in Naha, or head north for a taste of lovely scenery.
*Fun Fact: Workers in Japan and Okinawa DO NOT accept or work for tips. You could insult them by trying to leave one because they see service as a natural part of their work.*
Japan
I was offered a chance to head to Japan when I was 22 and still living in Okinawa. It is only a 2hr flight from the island! I was able to visit Kobe, Osaka, and Kyoto. If you are into history, I recommend Kyoto as a "must-see" since it is full of traditional cuisune and Japanese culture. If you want a bit more of the city life, Osaka is definitely the spot for you. The city is vibrant, colorful, and there is so much to do and see.
South Korea
I have been to South Korea a few times during my life because of family. My mother is from there and we would visit my grandmother and aunt during the summer. I had another opportunity to visit a friend of mine who taught English in Seoul. We mostly spent our time exploring the city and hot spots such as: Hongdae, Myeongdong, and Itaewon. For a perfect view of the city, I recommend N. Seoul Tower or Namsan Tower. Keep in mind, that Koreans believe in the importance of respecting one's senior. You show more respect to those either older than you or if they have been there longer than you have.