[4] On August 24, 2017, she was selected as a exclusive model of SMART School Uniforms, alongside fellow FNC Entertainment trainee Choi Yu-ju, which began on their marketing activities in September.

[5] Heo was introduced as a member of the upcoming girl group through Mnet's reality show Insider Channel Cherry Bullet.

[7] Heo made her acting debut in a romance web series Heart Way, which premiered on November 30, 2021.

[10] On October 26, 2022, Heo starred in a youth web series Disarming Romance.

[14] On April 22, 2024, the agency confirmed that Heo decided not to renew her contract and the group was officially disbanded.