Consisted of five dominantly EDM and dance-pop tracks, the extended play was produced and written mostly by production team MonoTree, with member MK and Wyatt contributed lyrically.

In addition, the label unveiled ONF's teaser images on their official social media platforms, portraying a half-open image in a pink envelope stamped with ON and OFF (ONF) stamps and contains a big letter with the message "#ㅅㄹㅎㄱㄷㄱㅇ", which was the Korean abbreviation for their upcoming album title.

[2] Two days later, WM Entertainment unveiled the first group pyro-photograph with all members wearing black and red costume, showcasing a "dark" and more "mature" image transition from their previous "bubbly" and "bright" images.

[6] Following the release of We Must Love, the group held an album showcase at the K-Art Hall at Olympic Park, Seoul, where they performed live the title track and "Yayaya" for the first time.

[10][11] The title track was then sampled and eventually re-arranged for the group's participation in Road to Kingdom, the male counterpart reality television program of Queendom that features seven rising boy groups competing with live performances of their previous singles and new recording.