In May 2014, after former Kara members Nicole Jung and Kang Ji-young left the group, DSP Media launched a reality TV show called Kara Project which revolved around seven trainees competing to become the new member of the group.

Even though she missed 2 live performances due to a leg injury from practice, she grabbed attention from viewers and topped the voting charts.

[6][7] She was known for her muted laughter, and on the Christmas special of Roommate, it was shown that Heo's family members have similar laughing styles as well.

[13][14][15] An MBC EVERY1 representative told MBN Star on December 18, 2014, that Heo would join Hitmaker season 2 as a part of a girl group, along with Orange Caramel's Lizzy, G.NA, 4minute's So-hyun.

[19] On January 15, 2016, DSP Media announced Gyuri, Seungyeon and Hara's departure from the group due to contracts expiring.

[20] On April 13, Park Gyu-ri stated that the group did not disband and that the members hoped to release new albums in the future.

On December 15, 2017, MCC Entertainment released news article that revealed she will participate on 2nd song of project 'with dog'.