Kim Oki was a former breakdancer and a backup dancer to Sechs Kies. He first learned saxophone when he was 25.[2] As for how he started the saxophone, he interviewed that after being impressed by Miles Davis' trumpet songs, he mistook him for a saxophonist at the time and learned to play saxophone.[7] He debuted in 2013 with his first studio album Cherubim's Wrath (천사의 분노), which he once said was inspired by a Jo Sehui's novel "The Dwarf."[8] He won Best Jazz & Crossover Performance at the 2014 Korean Music Awards.[9]
He was also active under the stage names of Kim Oki Oriental Youth (김오키 동양청년), Kim Oki Fucking Madness (김오키뻐킹매드니스), and Kim Oki Saturn Ballad (김오키 새턴 발라드).[10] He participated in Park Jiha's debut album Communion in 2016.[4] Lowdown 30's song Hotter featuring him won the Best Rock Song at the Korean Music Awards.[11]
He released his studio album Saturn Meditation (새턴메디테이션) in 2018, and an album Spirit Advance Unit (스피릿 선발대) in 2019.[12] Park Sangjoon of Music Y described the album as "Kim Oki's music sufficiently sheds light on certain poor lives, and certain lives that are mean and always prepared, even if he is not poor."[13] He won the Musician of the Year at the 2020 Korean Music Awards.[6][14]