On March 15, 2023, CTDENM announced via the group's official social media account that the upcoming second EP would be titled One of a Kind and was to be released on April 16.

[1][2][3] The release date was immediately met with backlash from fans, as April 16, 2024 was to coincide with the 10th anniversary of the sinking of MV Sewol.

[4][unreliable source] On March 19, the company posted on the group's fanclub site that the release date would be brought forward one day to April 15.

[5] The track list was released on April 12, with the music video teaser and highlight medley following over the course of the next two days.

[6][7][8] The EP and music video for the lead single "Girls' Night" were released at the same time at 6:00 PM KST on April 15, 2024.