It was announced in January 2021 that 2PM would make a full group comeback later in the year after
Junho completed his military service. On March 20, 2021, Junho became the final 2PM member to be discharged. On the same day, South Korean news outlet
Ilgan Sports reported that the group's comeback was scheduled for the summer. JYP Entertainment confirmed that 2PM was working on a new album while noting that “the exact timing of the release will be announced later on." On June 7, 2021, JYP Entertainment posted a video titled The Hottest Origins on its official social media channels. It revealed that 2PM's seventh Korean studio album, their first in almost five years since
''Gentlemen's Game, would be released on June 28, 2021, with the title Must''. During the group's hiatus, "My House", the title track of the group's 2015 album
No.5, climbed back to the top spots of multiple music streaming charts. The members said that the success of the song impacted the production of
Must. == Composition ==