The story takes place in South Korea in 1991. Hyun Jing (played by Ha Ji-won) is an excellent table tennis player who swept the country with momentum that year. With the goal of defeating China and winning the World Table Tennis Championships, Hyun Jing made unremitting efforts and practice. Just as the game was about to start, Hyun Jing learned an astonishing news that she had to form a partner with the North Korean table tennis player Lee Fenji (played by Bae Doona) to fight together. The relationship between North Korea and South Korea has always been in an ice age. This sudden cooperation made Hyun Jing very incomprehensible. She had no choice but to obey the "military order". In this way, a journey of cooperation full of ups and downs and contradictions began. Can Hyun Jing and Lee Fenji, who have completely different lifestyles and habits of dealing with people, cooperate successfully? Can they win the final victory? As the schedule approaches, the atmosphere becomes more and more tense.