Qoo Qoo in Suwon City (south of Seoul) was one of the best sushi restaurants I've been to. It's an all you can eat buffet with a large range of very fresh sushi, sashimi, salads, stir fry and deep fried foods. Soft drinks, deserts, fruits, and other assorted goodies are also included. We paid around $15 each and this money well spent. What was supposed to be a quick lunch turned out to be a three and a half hour degustation. Awesome! It's up a few flights of stairs and from memory there was a lift so no excuses.