Youngseo

1. Career

1.1. 2023–2024: R U Next? and departure from Illit prior to its debut

In June 2023, Youngseo was introduced as a contestant on R U Next?, a reality competition series aimed at forming a new girl group called Illit under Belift Lab.^[3] Throughout the program, she was consistently noted as one of the most popular trainees, eventually placing second overall in the finale on September 1, 2023.^[4] On January 5, 2024, Belift Lab announced that Youngseo had mutually agreed to terminate her contract and would no longer debut with Illit.^[5][6] Her departure generated significant media discussion, with publications describing her as a "standout trainee" whose future steps were highly anticipated by fans.^[7] In late 2025, reports emerged regarding allegations of mistreatment during her time as a trainee, with claims that Youngseo and other trainees were pressured to drop out of school to focus on their training.^[8]

1.2. 2025–present: Debut with AllDay Project and solo activities

On June 9, 2025, The Black Label revealed Youngseo as a member of their new co-ed group, AllDay Project.^[9] The group officially debuted on June 23, 2025, with the single album Famous.^[10] In an interview following her debut, Youngseo discussed her industry struggles, revealing that she faced significant self-doubt and initially believed her career window had closed before joining The Black Label, admitting she had previously felt "too old" to be an idol.^[11]

Youngseo has contributed to AllDay Project's music as a lyricist, with credits on tracks such as "You and I".^[12] In an interview with Clash Magazine, she discussed her active involvement in the track, noting that she spent significant time studying how to execute and express its vocal-heavy arrangements to showcase a new side of the group.^[12]

In November 2025, Youngseo participated in AllDay Project's performance at the inaugural Korea Grand Music Awards (KGMA).^[13] Following the event, where the group made history by winning the Grand Prize (Daesang) as a rookie co-ed ensemble,^[13] media attention surrounding Youngseo intensified and led to making her first independent projects in early 2026, including her debut solo magazine cover for the January issue of W Korea, which included a digital cover campaign in collaboration with the brand UGG.^[2][14] In March 2026, she appeared in solo pictorials and interviews for Elle Korea, where she was described as having a "definite cat-like charm",^[15] and shared insights into her personal life and style preferences, stating that she "loves everything cute that exists in the world".^[1]

2. Public image

Youngseo is frequently cited by South Korean media as a "standout member" of AllDay Project due to her extensive pre-debut history and established fan base from R U Next?.^[7][16] Her "cat-like" visuals and fashion-forward image have made her a sought-after model for digital campaigns and editorial features, often being highlighted alongside fellow member Annie Moon for their significant public impact prior to the group's official launch.^[1][16]

3. Endorsements

In early 2026, Youngseo collaborated with the American fashion brand UGG for a digital cover campaign.^[2][14] She has also participated in a rendezvous feature for Issey Miyake's perfumes in W Korea.^[17]

4. Discography

4.1. Songwriting credits

All song credits are adapted from the Korea Music Copyright Association, unless cited otherwise.^[18]

5. Filmography

5.1. Television shows

6. Awards and nominations