All of these trainees have been exposed to the public and gained popularity, but have never been able to debut.
1. Lee Soomin
Lee Soomin is currently a trainee under MYSTIC Entertainment. She first gained fame in Produce 101, where she competed as a trainee under Fantagio Music. She ranked #31 on Episode 10 and was eliminated. After Produce 101, she competed in Kpop Star 6 and was part of the top 4 before being eliminated. After, she participated in the YG Entertainment survival show MIXNINE. She ranked #2 in the girls ranking but the girl’s team lost to the boys, which means she would not be debuting.
She was originally supposed to debut under FAVE Entertainment’s girl group Fave Girls. She was part of the line-up until August 2018. She chose to leave the company and is now training under MYSTIC Entertainment.
Natty was first introduced to the public as a trainee under JYP Entertainment. She had participated in the survival show SIXTEEN, the show that brought us TWICE. She was only 13 years old when she joined the show and though she made it to the finals, she was not chosen for the debut line-up due to her age.
After SIXTEEN, Natty competed on Idol School. Though she was ranked #1 for her vocal ability and ranked high for both her dancing and her physical fitness, she failed to make it to the debut line up. Only 9 out of the 41 contestants would debut, and she ranked #13.
3. Go Yujin
Go Yujin gained fame when she competed in the Mnet survival show Produce 48. She competed as a trainee under Blockberry Creative. She was popular amongst Koreans due to her girl crush image and visuals, as well as her dance. She also gained fame with LOONA fans, as it was rumored that she was competing for a spot in LOONA, but failed to make the debut line-up.
She is currently a trainee under 8D Creative.
4. Kim Choyeon
Kim Choyeon also gained fame when she competed in Produce 48. She was well-loved due to her dance skills and over-flowing confidence. She is also well-known for her large eyes, which make her look pumped all the time. In the show, they called her eyes “fire eyes.”
Despite her popularity and skill, she ranked #50 in episode 8 and was eliminated.
5. Heo Yunjin
Heo Yunjin was a contestant in Produce 48 and represented PLEDIS Entertainment alongside After School member Lee Kaeun. She was well-known for her height; she is only 18 years old and stands at 170cm. She was called “giraffe” throughout the show. She also gained fame for being Korean-American and for her outstanding visual.
She ranked #26 during her time on the show and was eliminated during the semi-finals. Many fans hope that she will debut in a duo with Lee Kaeun or in a new girl group.
Koeun, also known by her full name Ko Eunji, was introduced as a member of SM Rookies back on July 8, 2015. She has been training for around 9 years and was part of the original debut line-up for Red Velvet. She did not make it, but did feature in Red Velvet’s music video for “Happiness.” She also featured in Super Junior Yesung‘s music video for “Paper Umbrella” alongside NCT‘s Jungwoo.
Lami first gained recognition as a child actor at the age of 8. She was introduced as a member of SM Rookies back on December 10, 2013. Known for her beautiful visuals, she played in numerous dramas, including Five Fingers, A Wife’s Credentials, Montage, and Winter Dream. She also made a cameo in Red Velvet’s music video for “Happiness.” Lami was also part of the Disney Channel show Mickey Mouse Club. She has been training under SM Entertainment for over 9 years.
Hina was introduced to the public as a member of SM Rookies back on July 8, 2015. With Lami, she was also part of the Mickey Mouse Club. She too made a cameo in Red Velvet’s “Happiness” music video.
Ningning first gained fame in China when she participated in the program Let’s Sing Kids. NCT Dream‘s Chenle also appeared on the program a season before Ningning did. She was introduced to the Korean public as a member of SM Rookies on September 19, 2016.
10. Han Chowon
Han Chowon was introduced to the public as a Cube Entertainment trainee when she participated in Produce 48. She was known for her singing ability and surprised everyone when she was given the main rapper position during their stage for “Rumor”. She was then named the “Reversal Queen” since everyone thought she would be a rapper by her visual, but then ended up being a main vocal, and then showing off her surprising rap skills.
She ranked #13 on the show. Since the final debut line-up would only consist of the top 12 trainees, she was unable to debut with I*ZONE.
11. Lily M
Lily M was introduced to the public as a contestant on the show Kpop Star 4. There, she ranked fourth runner-up and signed as a trainee under JYP Entertainment. Though she has released some singles, she has yet to make her formal debut. Lily M grew up in Australia and was born to a Korean mother and Australian father. She flew to Korea to pursue her career.
12. Moon Sua
Moon Sua gained fame when she competed on Unpretty Rapstar 2, as well as being ASTRO‘s Moon Bin‘s younger sister. She was introduced to the public as one of the four trainees of Future 2NE1. She had also featured on G-Dragon and T.O.P‘s music video for their song “Knock Out”. She had trained under YG Entertainment for 10 years before she left. It is unknown if she has signed with another company.
13. Takeuchi Miyu
Takeuchi Miyu has made her Japanese debut, but not her Korean debut. In 2009, Miyu made her debut as a member of Japanese girl group AKB48 under Team B. In 2018, she appeared as a contestant for Produce 48 as a “trainee” under AKB48. She ranked #18 on the show and didn’t make the final line-up. Shortly after the show, she announced that she was graduating from AKB48 on September 4, 2018. She officially left the group on December 23, 2018.
On March 8, 2019, it was confirmed that she signed with South Korean music label MYSTIC Entertainment. It is unsure if she will debut as a soloist or part of a girl group.
14. Lee Sian
Lee Sian was first introduced to the public as a contestant for Idol School. There, she ranked #16. She then signed as a trainee under Stone Music Entertainment and competed in the survival show Produce 48. Despite her dance skills and stunning visuals, Sian ranked #30 during her time on the show and was eliminated.
15. Hwang Soyeon
Hwang Soyeon also competed in Produce 48. During her time on the show, she was a Wellmade Yedang trainee. She gained fame during her auditions, where she was told she looked like Sunmi. She was then made to freestyle dance to Sunmi’s song “Gashina”, where she wowed the judges with her dance skills. Despite her skills, she ranked #60 and was eliminated from the show.
She is currently a trainee under MNH Entertainment alongside fellow Produce 48 contestant Lee Haeun. MNH Entertainment currently houses artists like Chungha.
16. Kim Taedong
Kim Taedong was first introduced to the public when he competed on the show Boys24. He did not make the final line-up and was eliminated from the show. He then went on to competed in Produce 101 Season 2 as a trainee under The Vibe Label. He ranked #30 and did not make the group.
He was originally set to debut under the fan-made project group JBJ. However, issues with his company caused him to terminate the contract. He claimed he was being mistreated by the company and was then unable to debut under JBJ. For a while, Taedong trained independently and worked part-time at a cafe. In November of 2018, Taedong announced via a hand-written letter posted to his Instagram that he reconciled with his company, Major 9 (previously named The Vibe Label).