The son of Korean immigrants to Germany, he began playing ice hockey at the age of 5, progressing his way through local youth leagues and into the Krefeld Pinguine's youth development system. He became a regular player for the German Junior National Team. In 1997 he was called up by Coach Miroslav Berek and Manager Rüdiger Noack to begin the season with the Elite league team at the age of 17, where he scored two goals in five preseason games playing alongside former NHLer Peter Ihnacak. Hyun played most of the season with the second-league playing development team. In 1998 Hyun decided to go to the United States to further his education and pursue his hockey career at the same time. He first studied at Benilde-St. Margaret's High School, a Catholic school in St. Louis Park, Minnesota, later transferring to Northwood Prep School in Lake Placid, New York.