Lee Sang-hoon, born on April 15, 1997, in Wonju, Gangwon Province, is known by his stage name Gonghoon, which he created during his high school days, pondering the possibility of becoming a singer during self-study periods. Raised primarily by his grandmother, he was naturally exposed to trot music, believing it to be the only form of music that existed, influenced by the lullabies she sang and trot medleys. Gonghoon earned nicknames like "Grand Prize Collector" and "Elite Trotman" after winning multiple awards at singing competitions, which he viewed as a stepping stone to his dream of becoming a trot singer. Despite his passion, he couldn't openly pursue a singing career due to his mother's illness, which confined his performances to school festivals. His break came when he performed Oh Seung-keun's "What's My Age" at a high school festival, a performance that turned him into a school sensation, despite his initial fears of being ridiculed for his trot singing among teens. A devout fan of Na Hoon-a, Gonghoon decided to pursue singing professionally after attending Na Hoon-a's concert at 21, which left him thrilled and supported by his mother, who had anticipated his aspirations. Following his military service, where he sang Na Hoon-a's "Broken Wall Clock" at a national singing contest and won a top award, he debuted with the digital single "Let’s Live Coolly" on February 13, 2020. His career further blossomed as he won a trot contest for young singers on MBC and secured a contract with SIMPLE ENTER in August 2021 through the recommendation of fellow singer Shin Mi-rae. He has then released multiple singles, including "Why Can't I Love You", released in 2025.