Oneus (Hangul: 원어스, stylized as ONEUS) is a South Korean boy group formed by RBW. The group released their debut EP, Light Us, on January 9, 2019. The group consists of six members: Ravn, Seoho, Leedo, Keonhee, Hwanwoong and Xion.
Seoho, Keonhee and Hwanwoong were introduced as half of the male trainees to represent RBW on the second season of Produce 101 during the first half of 2017. However, they were eliminated in the 94th place, 33th place and 42th place respectively. Ravn and Seoho participated as half male trainees to represent RBW on the YG survival show, Mix Nine during the second half of 2017, where they were eliminated in the 27th place and 19th place respectively. Lee Do participated Mix Nine as individual trainee, however, he did not pass the first audition.
In November 2017, RBW introduced debut project named RBW Trainee Real Life – We Will Debut to launch their boy groups. Keonhee, Hwanwoong and seven other trainees (three male and four female) made their participation in the first chapter of the project in which they invited 100 people to be their audience in the evaluation stage at RBW Art Center.The project would hold events or performances each month and the trainees daily life, consisting of monthly training and evaluations would be aired on Olleh TV and Naver’s V-Live. In December 2017, Keonhee and Hwanwoong participated in the second chapter ‘Special Party’ with their labelmates MAS.
In early 2018, Keonhee, Hwanwoong and other trainees: Ravn, Seoho and Xion were introduced as pre-debut team RBW BOYZ. In April 2018, RBW Boyz introduced their new member Leedo.In June 2018, RBW BOYZ was confirmed to be debut as ONEUS. On September 27, ONEUS and their labelmates ONEWE (formerly MAS) released official single “Last Song”.
On January 9, ONEUS officially made their debut with the release of their first EP Light Us with the title track “Valkyrie”. Their debut showcase was held at the YES24 Live Hall on the same day as the album’s release.