Square Up is the first Korean mini-album by BLACKPINK. It is available in two versions and contains 4 tracks, with "Ddu-Du Ddu-Du" and "Forever Young" serving as the album's double title tracks. "Square Up", which means "stick together" and "prepare to fight", has a message of "let's stand up to the challenge", exploring a mature concept. The album was released digitally on June 15, 2018, and physically on June 20, 2018.
On April 24, 2018, CEO of YG Entertainment, Yang Hyun-suk raised expectations of the group's comeback via SNS stating that by the end of this year Black Pink will return with new music soon. And on May 17, he revealed the month of June for the release while answering fan asked questions on SNS. It wasn't until May 25, he confirmed the date June 15 and revealed the album. On June 1, the album's moving poster was unveiled, followed by full track list on June 5 and the individual moving poster of the members simultaneously.