In August 2019, AOA joined Mnet's reality survival show Queendom, which saw six female K-pop acts competing in a series of preliminary performances, and in the show's finale, each act would release a final song on the same day to compete for the top spot. The series began airing on August 29, and following the premiere, AOA had begun to receive a lot of positive reception and widespread attention for their appearances on the show. The performance for their cover of Mamamoo's "Egotistic" became a trending topic on Naver, and the digital release of their cover entered many Korean music charts. On October 25, Queendom's six contestants released their final songs on Korean streaming services. AOA released "Sorry," which would be their first official release as five members.
