It is a must for every idol to go through intense training programs to chase their dreams and a requirement before completely debuting as an artist. This really showed how much dedication and determination they have to debut, as well as a preparation to have a successful career.
The training period may vary depending on the trainee, and if they are fortunate enough, they can debut as soon as possible. Though the training period is not an instrument to measure one's skills, some are, unfortunately, left and were trained for a long time regardless of their incredible talents, which made them eventually think to give up on becoming an idol.
But thanks to their passion and persistence to wait, their major debut date came and look at them now, despite the long path they took, it is all worth it as these K-pop idols become some of the most successful icons in the whole K-pop industry.
BIGBANG's G-Dragon (11 years)
For his 11 years of being a trainee, G-Dragon spent five years in SM Entertainment, and the rest of his training years was spent on YG Entertainment until he became a member of BIGBANG.
ITZY's Chaeryeong (5 years)
Most of us know that the Lee sisters competed together in JYP's survival show SIXTEEN. And after the show ended, she stayed at JYP Entertainment until she debuted as a member of ITZY early 2019.
SEVENTEEN's S.Coups (6 years)
S.Coups, the group's leader, trained for the longest out of all the SEVENTEEN members. He was actually one of the first male idol trainees from PLEDIS Entertainment that he almost debuted with NU'EST.
NCT's Johnny (9 years)
Johnny joined the company in 2008, which is the same year that SHINee debuted. With this information, it can be confirmed that he became the longest trainee that debut with NCT. He could have also debuted with EXO in 2012. It was said that he does not still feel ready and waited until NCT's debut in 2017.
Red Velvet's Seulgi (7 years)
The main dancer from Red Velvet, Seulgi, actually became a part of SM Rookies and three other members. She actually began her training during her first year of middle school in 2007!
TWICE's Jihyo (10 years)
Jihyo started training at the incredibly young age of 8, that everyone has seen her iconic audition video. This proved that she spent most of her childhood, preparing to become an idol.
BLACKPINK's Jennie (6 years)
The YG Princess, Jennie, started training under YG Entertainment in 2010. Later on, she gained attention in 2012 when she was introduced as a potential member of the company's second girl group after 2NE1.
MOMOLAND's Nancy (6 years)
Nancy originally trained under Nega Network and even appeared on Korea's Got Talent back in the days. She then later earned first place on the reality show Finding Momoland and became the visual of the group.
ASTRO's Moonbin (7 years)
ASTRO's center actually started off as a child actor and model in the entertainment industry. As he wanted to pursue his career, he joined Fantagio in 2010 and named as the most extended training member in ASTRO.
(G) I-DLE's Miyeon (8 years)
Miyeon started as a trainee under YG Entertainment for five years and could have possibly debuted with BLACKPINK. Until she moved to Cube Entertainment in 2015, where she was able to join (G)I-DLE.
Wanna One's Former Member Yoon Jisung (5 Years)
The former leader who managed to debut through Produce 101 Season 2 was able to flourish after missing three chances to debut under MMO Entertainment.
MONSTA X's Shownu (7 years)
The leader of MONSTA X, Shownu, actually trained under JYP Entertainment for two years before moving to Starship Entertainment.
EXO's Suho (6 years)
This leader of EXO, namely, Suho, became one of the most extended trainee periods out of anyone from EXO after he auditioned for SM Entertainment's global casting auditions in Changsha.
ACE's Jun (9 years)
Jun became a trainee under three companies, namely, Jellyfish Entertainment for seven years, Stone Entertainment for one year, and Beat Interactive for another year until he became a member of the group ACE.
G.Soul (15 years)
G.Soul has the most prolonged trainee period out among idols. After working for 15 years under JYP Entertainment, he finally debuted as a solo artist in 2015.
