[11] Kim was first selected for the senior national team in 2004 and won gold at the Seoul Grand Prix in 2005 despite being a relative newcomer.

[12] However, his medal was forfeited and he was suspended for a year after failing a doping test, which he unsuccessfully argued was due to medication he had taken at home to treat his insomnia.

The slump in form coupled by the sudden death of his father, who he was close to, in 2009 nearly led him to quit the sport altogether.

[13][15] He enlisted for mandatory military service in January 2010 and was assigned to the Korea Armed Forces Athletic Corps.

[21][17] He was awarded the Order of Sports Merit Cheongnyong (청룡장; English: Blue Dragon) class, the South Korean government's highest honor bestowed on professional athletes who meet the criteria.

[22][23] In 2018, he and his teammates Gu, Oh Sang-uk and Kim Jun-ho, swept gold in the team sabre event at both the World Championships and the Asian Games.

[27] At Gu's persuasion, he returned to the national team and qualified in time for the Seoul Grand Prix held in April 2019, winning bronze.

[28] He joined the same teammates from the 2018 World Championships and Asian Games and they qualified for the 2020 Summer Olympics, which was later postponed for a year due to the COVID-19 pandemic.