Sechs Kies and retirement Ko was recruited by Kang to join the boy band he and his high school friend
Eun Ji-won were forming. The group was eventually named
Sechs Kies and debuted on April 15, 1997. Ko was the second youngest member. Until the time the group disbanded in 2000, he was greatly loved by fans for his handsome looks and singing voice. Unlike other members, he did not continue his career as a solo singer but he was cast as a host in an internet broadcast and as an actor in a television drama. However, Ko chose to leave the entertainment industry to start his own business. In 2008, fellow Sechs Kies member and leader
Eun Ji-won appeared in the entertainment program
Come to Play and remarked that he had not seen Ko since the group's disbandment. Fellow vocalist
Jang Su-won revealed on
Happy Together in 2014 that he was in contact with Ko and confirmed that he was running his own business.
Reunion In 2016, Sechs Kies reunited after their disbandment in 2000 through the variety show
Infinite Challenge. Ko, who had left the entertainment business permanently after the disbandment to pursue a new career, surprised the members of SechsKies as well as all the fans by appearing at the reunion concert and performing their hit song "Couple". After Infinite Challenge aired, Sechs Kies earned many more fans; their hit songs ranked high in music charts and “Couple” was seen in 11th place in Music Bank. The group officially reunited and signed a group contract with
YG Entertainment in May that year. However, Ko was the only one who did not sign, having been the only member to depart from the entertainment industry completely. On July 18, Ko publicly appeared as a sponsor for a charity basketball event and held interviews with the media for the first time in 16 years. He stated that he is now living as a "half-celebrity" since appearing on
Infinite Challenge. On November 30, it was announced that Ko and his son would be joining the cast of
The Return of Superman. He said although he cannot participate in current Sechs Kies group activities as a family man, he has determined to keep his promise to "create opportunities to be with fans through activities he can participate." Also as he was unable to spend more time with his son, he hopes to make many memories with him through the program. In May 2019, Ko announced that he and his son would be leaving the cast of 'The Return of Superman'. == Personal life ==