She steadily gained recognition as the youngest and first female recruit of the "world-class" dance crew, Just Jerk, and propelled to domestic stardom following her appearance on Street Woman Fighter (2021).

Leejung was raised Christian and attended The King's Academy in Tennessee, United States for 4–5 years during sixth grade of elementary to end of middle school.

[5][6] Amidst her stay, her parents humorously proposed if she became the top student in her school, they'd allow her to receive dance lessons in South Korea during summer vacation.

Although they were rendered speechless, her parents allowed her to receive two months of lessons at age 16, her first formal experience to learn the art of dance.

Her father yielded to her aspirations with an ultimatum, if she didn't show any result within the dance scenes within a year, she'll depart back to the states.

[7][5] In the time Leejung spent as part of Just Jerk, she participated in multiple dance competitions and also served as one of their English interpreters while abroad.

Just Jerk received an invitation via phone call from the casting director to appear on the twelfth installation of their show that was scheduled for broadcast in 2017.

[10] With only a year of preparation, Leejung and her team salvaged and earned money for plane tickets, accommodation for one month, car rentals, and meals.

[16] Leejung was also scouted to take on the role of a dance trainer for Nayeon and Momo of Twice, Rosé of Blackpink and Jeon Somi by their respective agencies.

[24] As the only female in the then-male dominated crew, she was put in the spotlight for her age, skills and gender and became a well-known figure for Generation MZ.

[19] Many identify Leejung by her signature "Pucca" hairstyle, lip ring and red lipstick and is often portrayed using these trademarks when re-enacting her, namely seen by Taeyeon of Girls' Generation, comedian Jo Se-ho and Aiki of Hook.

[21] Leejung with the members of YGX—which include Yeojin, Jihyo, Isak and Yell—filmed promotional videos for the campaign "Unstoppable Joy" (2021) in collaboration with BMW Korea.

[35] Fashion shopping app Brandi announced, after the launch of its "One Day Delivery" campaign with YGX in November 2021, the amount of transaction had grown 130% compared to the previous month.

She endorsed for oral hygiene brand Toosty,[39] Paris Baguette,[40] Nike X Peaceminusone's Kwondo 1,[41] TikTok Korea with Mino of Winner and Part-timer Heaven alongside Jeon Somi.