The American hamburger concept continues to be ever popular throughout the world. Johnny Rockets has expanded into the Korean market, partnering with Shinsegae Food Co. to open its first restaurant in that country. Shinsegae plans to open five restaurants in Korea during the next five years. The 1,067-sq.-ft. Johnny Rockets restaurant is located in a Seoul department store owned by its partner’s parent, Shinsegae Group. Johnny Rockets is based in Aliso Viejo, Calif.