1THE9

1THE9 (stylized as 1THE9, pronounced “Wonder Nine” and known in Korean as 원더나인) was a nine-member South Korean project boy group formed through the 2018 MBC survival competition Under Nineteen. Selected from 57 trainees by nationwide audience voting, the final lineup – Yongha, Taewoo, Seunghwan, Yechan, Junseo, Doyum, Jinsung, Taekhyeon, and Sungwon – debuted on April 13, 2019 under MBK Entertainment, managed day-to-day by PocketDol Studio. Their debut mini album XIX, led by the single “Spotlight” and pre-release track “Domino” (featuring Crush), introduced the group’s bright, youthful concept and peaked at number 7 on the Gaon Album Chart.

Over their short run, 1THE9 released three more EPs – Blah Blah (2019), Turn Over (2020), and the farewell release Good Bye 1THE9 (2020) – steadily maturing their sound from candy-pop energy toward a moodier, more confident concept typified by the title track “Bad Guy.” Fans, known as Wonderland and represented by the fan color Lime Punch, supported the group through a contract period that was extended due to the COVID-19 pandemic before the group officially disbanded on August 8, 2020.

Though their promotional period was brief, several members went on to notable second acts: Yongha and Junseo debuted in WEi, Yechan joined OMEGA X, Doyum joined JUST B, Taewoo joined BLANK2Y, and Sungwon debuted in Ciipher before launching a solo career. 1THE9 remains remembered as one of the more overlooked “survival show” project groups of its era, valued by fans for its tight vocal work and the individual member journeys that followed.