South Korea U20

Red Fury (1983)

South Korea's under-19 team, which finished third in the qualifying tournament, was initially ineligible to play in the final stage of the 1982 AFC Youth Championship. However, the North Korean FA was punished with a two-year suspension for assaulting a referee at the 1982 Asian Games by the Asian Football Confederation, so South Korea advanced to the final stage instead of North Korea, the runners-up. After winning the tournament, South Korea qualified for the 1983 FIFA World Youth Championship as Asian champions. Manager Park Jong-hwan trained his team with tactics that demanded a lot of endurance and teamwork for the World Youth Championship.

Drawn in a group with Scotland, Australia and the host Mexico, South Korea lost their first game against Scotland, but they advanced to the knockout stage by defeating the other two teams. In the quarter-finals, they faced Uruguay, and won the game 2–1 with two extra time goals by Shin Yon-ho. The news that they reached the semi-finals for the first time in a FIFA competition became a myth in South Korea, a weak country in sports at the time, although it was a youth competition. The foreign press was also interested in South Korea's achievement, describing it as the "Red Fury". South Korea finished the tournament in fourth place after losing to Brazil and Poland, and South Korean defender Kim Pan-keun was named in the official All-Star Team. The name of "Red Devils", the supporters' group for the South Korean national team, was inspired by this story.

Korean unified team (1991)

The Inter-Korean Sports Conferences were held on the recommendation of the International Olympic Committee since 1963, but the conferences always broke down until the 1980s because both sides had not seen eye to eye. In February 1991, however, they decided to make Korean unified teams in table tennis and football. In that same year, both South and North qualified for the FIFA World Youth Championship as winners and runners-up of the 1990 AFC Youth Championship, so they urgently made allied under-20 football team for the world championship despite concerns about communication and teamwork. Their challenge was ended in the quarter-finals.