2000-2018: Early life and career beginnings
HeeJin was born as Jeon Heejin on October 19, 2000 in Bundang-gu, Seongnam, Gyeonggi Province, South Korea. She is the youngest of three daughters in her family. HeeJin's decision to become a singer occurred in middle school. At one time, both her sisters had similar dreams to hers, but they remained unfulfilled. She has stated that one of the reasons she became a singer was to make her sisters’ unfulfilled dreams come true and has cited her sisters as being her biggest supporters. For this, she traveled long distances in order to attend a dance academy. Her father began discouraging her dreams of becoming a singer after she was rejected at several auditions. However in 2015, she was casted through social media by BlockBerryCreative and became a trainee. HeeJin trained for 1 year before she was selected to be the first member of the agency's upcoming girl group.
On September 26, 2016, HeeJin was revealed as the first member of girl group LOONA, and released her pre-debut single on October 5, 2016.
In October 2017, HeeJin, along with fellow LOONA members HyunJin and HaSeul, auditioned for survival reality show Mix Nine. Having passed the audition, she became a contestant, as a representative of her agency and idol group. HeeJin made it until the final episode, where the boy's team won against the girl's, and hence ultimately did not get to debut.
- "HeeJin" (2016) (pre-debut)
- Her nickname is Heekki (희끼), which is a portmanteau of her name and the word for rabbit (토끼). She originally give this name to the rabbit she met on set while filming her first MV.
- Her role models are Girls' Generation's Taeyeon and Shim Kyusun (Lucia).
- Her goal is for LOONA to become the best girl group in Korea, and to become a singer that others can look up to.
- In the audition, she sang Lyn’s ‘Ring Tone’ and got accepted.
- HeeJin likes animals, but is allergic to animal fur. She also has a fear of birds, especially pigeons.
- HeeJin really likes bread, she visits bakeries as a hobby. She says the taste of European bread is best.
- HeeJin can twist her tongue from side to side.
- HeeJin revealed that as a trainee, she lived in the countryside and had initial difficulties attending training because she lived over 4 hours away from Seoul, didn't have enough training time and struggled financially with affording transportation. She currently lives in a dorm with the other LOONA members, and shares a room with HyunJin, HaSeul and ViVi.