Gyuen Dang Seongsu Main Branch is a Japanese restaurant near Exit 3 of Seongsu Station in Seoul, serving tenderloin and sirloin gyukatsu along with curry. The gyukatsu is crisp outside and moist inside, and diners grill it themselves on a personal brazier to their liking. The tenderloin gyukatsu comes medium rare and can be cooked further on the individual brazier. There is a wait in the evening.