2020: Formation, debut, and Monster 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 would release their first extended play in June. 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. 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. Their cover was well received by the public and
Lee Soo-man, which eventually prompted the creation of their subunit. They also had several performances together during
SM Town Live Special Stages. On July 6, Red Velvet – Irene & Seulgi released their debut extended play
Monster, which contained six tracks, including the singles "
Monster" and "
Naughty". With the release of their debut album, they became the best selling female sub-unit in South Korea in 2020. The duo made their debut performance on July 10 on
Music Bank. 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!. Before their performance of "Monster", they also offered a message of appreciation and support to the frontliners during the COVID-19 pandemic. On April 14, they announced their first Asia tour,
Balance, kicking off in Seoul on June 14. On May 7, SM Entertainment announced that the duo's second extended play
Tilt would be released on May 26, with the lead single of the same name. On December 31, the duo performed at Let's Celebrate 2026 countdown show held in
Sentosa Siloso Beach in Singapore. ==Discography==