The story of the pre-debut trajectory of the four girls previously known under the group name A-MIX has extended with yet another chapter.

The story begins with the creation of Flossom under Two-H Company and NW Studios. Originally the group was intended to be a collaboration project between the members of ZZBae (NW Studios) and Sunny Play (Two-H Company). But with the disbandment of ZZBae in May of 2018 and the unofficial disbandment of Sunny Play, Flossom seemed on their way to becoming a fixed group for the girls: Ebin, Hana, Yuha, and Jane. At this point, the fifth member Haelee, who was in ZZBae with Ebin, had already left the group. This is, however, the point their line-up started to change regularly. First, a new member was introduced by the name of Somin, also a Sunny Play member. Which was followed swiftly by the news that Ebin, Yuha, and Jane had left the group. In their stead, Zena and Seohwa were added. Zena left rather quickly as well, after being offered the opportunity to debut solo under the company. The group started teasing two new members, but only Hyoa was officially revealed. She was last to join and last to leave. 

In October 2018, Flossom was announced to have disbanded and were introduced through the new group A-MIX, which would be a Two-H Company (though by then the company had rebranded as MAKE D) exclusive group. Only Hana remained from the last Flossom line-up. She was joined by Mirae, Remi, and Yena, whose profiles were revealed throughout November and December 2018. The group went quiet in December, however.

On the 20th of January, it was discovered the girls had left MAKE D company and joined Monster Company under their new group name Swalla through an Instagram post made by Monster Company. One day after the group held their first performance under their new name.

Check out their performance below!