On February 17, 2019, Yue Hua revealed that they would debut a new girl group named EVERGLOW. On the same day, they opened the staff and group's Twitter, Instagram, and Fancafe accounts. On the group's social medias, a teaser was posted revealing the official logo of the group. On February 18, an article was published on Naver, revealing that former Produce 48 contestants Kim Sihyeon and Wang Yiren were included in the group's lineup. Later that same day, a teaser video was posted on Stone Music Entertainment's channel on YouTube, confirming Sihyeon as the first member. The following day, Mia was revealed as the second member, followed by Onda on the 20th,Yiren on the 21st,E:U on the 24th, and Aisha on the 25th.
On March 3, 2019, the concept photos of the group and the members was revealed. On March 6, the group revealed their schedule list for the debut album.
EVERGLOW debuted on March 18 with the single album "Arrival of EVERGLOW" and its title track "Bon Bon Chocolat". They held their debut stage on the 21st on M Countdown.
On August 19, the group released their second single album "Hush" and its title track "Adios". At their comeback showcase on the same day, they revealed their fandom name to be "Forever" after the group's desire to be with their fans forever.