Red Velvet - Irene & Seulgi

On April 21, 2020, SM Entertainment revealed that Irene and Seulgi would form Red Velvet's first sub-unit. On the same day, it was announced that the unit will release their first extended play in June.[1] The release of the mini album was later postponed on the grounds that it needed additional production on the album, in order to achieve a higher quality of music.[2]

Before their debut as members of Red Velvet, the duo, as part of SR14G (SM Rookies 2014 Girls), notably performed a cover of "Be Natural", a song that was sung originally by S.E.S.[3] Their cover was well-received by the public and Lee Soo-man, which eventually prompt for the creation of their sub-unit due to their amazing chemistry together.[4] They also had several stunning performances together during SM Town Live Special Stages.[5]

On July 6, Red Velvet - Irene & Seulgi released their debut extended play Monster, which contains six tracks, including the singles "Monster" and "Naughty".[6] The duo made their debut performance on July 10 on Music Bank.[7] From July 8 to September 8, the duo also starred in their own reality show, a spin-off of their group's Level Up Project!.[8] In August 18, 2020, Irene & Seulgi appeared and performed at TIME100 Talks, a live event series wherein global leaders talk about innovative solutions to urgent global problems, and encourage cross-disciplinary action among stakeholders.[9] Before their performance of Monster, they also offered a short support and appreciation message to the frontliners during the COVID-19 pandemic.[9]