The group originally consisted of six members: Moon Sua, Suhyeon, Haram, Tsuki, Siyoon and Haruna.

[6][7] Suhyeon participated in the Mnet survival program Produce 101 placing 69th and eliminated in the fifth episode.

[9] Sheon participated in the Mnet survival program Girls Planet 999, and was eliminated in the final episode placing tenth.

[10] Siyoon participated in the talent show K-pop Star 5 and also worked as a model for the magazine Popteen.

[22] On April 20, Mystic Story announced that the group's activities have been halted, due to the sudden death of Moon Sua's brother Moonbin of Astro.

[26] Members Moon Sua and Suhyeon would not be involved in this release due to their hiatuses from health issues.

[27] On April 12, 2024, it was announced that members Moon Sua and Suhyeon would resume activities after being on hiatus due to health issues.

[29] The music video teaser for the lead single "Remembrance Candy" (Korean: 기억사탕; RR: Gieoksatang) includes a special narration by singer-songwriter IU, who also wrote the lyrics for the song.