Longest K-pop Training Periods: 15 Idols Who Trained Hard

When we watch idols perform on stage with their perfect dance moves and bright smiles, we don’t see the years spent in practice rooms before that moment. Some K-pop idols trained for 7 to 15 years before they could stand on stage for the first time. 

The difference between their glamorous debut and the struggle behind it is massive. That long training period is exactly what makes their success feel real and earned. 

In this article, you’ll learn about 15 idols who had the longest training periods and what kept them going when things got really hard.

Who Trained the Longest in K-Pop?

G.Soul trained for 15 years at JYP Entertainment. That makes him the record holder for the longest training period anyone has officially confirmed in K-pop. 

He began his training at JYP as a teen and launched his solo career in 2015 in the R&B genre. 

His story is really unusual because most trainees either debut or quit within 3-5 years. Today, G.Soul is recognized as a talented R&B artist, showing that his patience finally brought real results.

Longest K-Pop Training Periods: At A Glance

Here are the idols ranked by training duration, highlighting the extreme dedication required in the K-pop industry and their current status as of 2026.

Rank	Idol	Agency (Primary)	Training Period	Status in 2026
1	G.Soul	JYP Entertainment	15 Years	Record holder; now a highly respected R&B soloist.
2	Moon Sua	YG / Mystic Story	12 Years	Active in Billlie; legendary for her 10-year YG “Future 2NE1” stint.
3	G-Dragon	SM / YG	11 Years	Global icon; famously spent 5 years at SM before 6 at YG.
4	Aisha	JYP / Yuehua	11 Years	Active in EVERGLOW; spent 9 years at JYP before moving.
5	Jihyo	JYP Entertainment	10 Years	TWICE Leader; joined JYP at age 8 and debuted at 18.
6	Seola	Starship / Various	10 Years	WJSN member and soloist; trained since 2006.
7	Natty	JYP / Swing / S2	10 Years	Active in KISS OF LIFE, a decade-long journey through survival shows.
8	Kwangjin	FNC Entertainment	10 Years	Former N.Flying; trained for a full decade under FNC.
9	Jaehyun	FNC Entertainment	10 Years	N.Flying drummer; another decade-long veteran of FNC.
10	Johnny	SM Entertainment	9 Years	NCT 127; joined in 2008 and trained alongside EXO members.
11	Xiyeon	Pledis Entertainment	9 Years	Former PRISTIN; joined Pledis as a child at age 9.
12	Jinho	SM / Cube	8 Years	PENTAGON/Soloist; debuted in SM The Ballad before moving to Cube.
13	Moonbin	Fantagio	8 Years	ASTRO; first-ever Fantagio trainee, starting in 5th grade.
14	Bang Chan	JYP Entertainment	7–8 Years	Stray Kids Leader; joined JYP in 2010.
15	Seulgi	SM Entertainment	7 Years	Red Velvet, known as SM’s “Ace,” who trained from 2007 to 2014.

The time each idol spent training is based on company announcements, idol interviews, and trusted reports.

Below, we’ll break down each idol’s story in detail.

1. G.Soul – R&B Soloist

Joined as Trainee (Year / Age)	2000 (Age 15)
Agencies Trained Under	JYP Entertainment
Total Training Duration	15 Years
Debut Year	2015
Key Milestone or Turning Point	Longest verified training in K-pop history

G.Soul, a Korean-American R&B singer, owns the longest training record in K-pop at 15 years. He joined JYP in 2000 as a teenager with big dreams. 

Fifteen years passed before his solo debut in 2015. During that time, he watched multiple groups debut and disband while he stayed in the practice room. His story shows that sometimes the longest wait leads to the most respect in the industry.

2. Moon Sua – Billlie

Joined as Trainee (Year / Age)	2006 (Age 8)
Agencies Trained Under	YG Entertainment, Mystic Story
Total Training Duration	12 Years
Debut Year	2021
Key Milestone or Turning Point	10 years at YG as a “Future 2NE1” member

Moon Sua is a Billlie member whose training story has become well-known in the K-pop community. She trained at YG from age 8 as part of a project called “Future 2NE1” that never happened. 

After 10 years without debuting at YG, she moved to Mystic Story. She finally debuted with Billlie in 2021, proving that giving up isn’t always the answer, even when things look hopeless.

3. G-Dragon – BIGBANG

Joined as Trainee (Year / Age)	1997 (Age 8)
Agencies Trained Under	SM Entertainment, YG Entertainment
Total Training Duration	11 Years
Debut Year	2006
Key Milestone or Turning Point	Trained at SM for 5 years before switching to YG

G-Dragon is currently one of the most followed K-pop idols on Instagram with 25M followers. He’s a global icon who trained for 11 years across two major companies. 

He started at SM Entertainment at age 8 and stayed for five years. Then he switched to YG in 2001. After six more years of hard training, he debuted with BIGBANG in 2006 and became one of the most important artists in K-pop history.

4. Aisha – EVERGLOW

Joined as Trainee (Year / Age)	2008 (Age 9)
Agencies Trained Under	JYP Entertainment, Yuehua Entertainment
Total Training Duration	11 Years
Debut Year	2019
Key Milestone or Turning Point	9 years at JYP before the company change

Aisha is an EVERGLOW member whose training lasted 11 years across two different companies. She trained at JYP for nine years, starting at age 9. 

She appeared on Sixteen but didn’t make it into TWICE. That must have been heartbreaking after so many years. But she didn’t quit. She moved to Yuehua and trained for two more years before finally debuting with EVERGLOW in 2019.

5. Jihyo – TWICE

Joined as Trainee (Year / Age)	2005 (Age 8)
Agencies Trained Under	JYP Entertainment
Total Training Duration	10 Years
Debut Year	2015
Key Milestone or Turning Point	Youngest trainee at JYP in 2005

Jihyo is the leader of TWICE and a perfect example of how patience pays off. She joined JYP at age 8 in 2005, making her the company’s youngest trainee at that time. 

For 10 years, she trained while other groups debuted around her. She survived the Sixteen survival show and finally debuted as TWICE’s leader in 2015 at age 18. Her decade of training shaped her into the strong leader TWICE needed.

6. Seola – WJSN

Joined as Trainee (Year / Age)	2006 (Age 13)
Agencies Trained Under	Starship Entertainment, Various
Total Training Duration	10 Years
Debut Year	2016
Key Milestone or Turning Point	Trained since middle school

Seola is a WJSN member and soloist whose training started when she was just in middle school. She began her trainee life in 2006 at age 13 and spent a full decade preparing. 

During those years, she went through multiple times when her debut was pushed back. But she kept going and finally joined WJSN’s lineup in 2016 as a lead vocalist. Her voice made the wait worth it.

7. Natty – KISS OF LIFE

Joined as Trainee (Year / Age)	2012 (Age 10)
Agencies Trained Under	JYP Entertainment, Swing Entertainment, S2 Entertainment
Total Training Duration	10 Years
Debut Year	2023
Key Milestone or Turning Point	Sixteen contestants at age 14

Natty is a KISS OF LIFE member whose path to debut took 10 years and went through three different companies. She joined JYP at age 10 and competed on Sixteen when she was just 14. 

After leaving JYP, she appeared on Idol School and kept training under different agencies. Most people would have given up, but she didn’t. She finally debuted with KISS OF LIFE in 2023.

8. Kwangjin – Former N.Flying

Joined as Trainee (Year / Age)	2003 (Age 14)
Agencies Trained Under	FNC Entertainment
Total Training Duration	10 Years
Debut Year	2013
Key Milestone or Turning Point	Full decade at a single agency

Kwangjin was a former N.Flying member who trained for exactly 10 years under FNC Entertainment. He joined FNC in 2003 as a teenager and spent the entire 2000s decade training. That’s his whole high school and college years gone. 

After 10 years of waiting, he made his debut with N.Flying in 2013. He later left the group, but his training period remains one of the longest in K-pop.

9. Jaehyun – N.Flying

Joined as Trainee (Year / Age)	2003 (Age 13)
Agencies Trained Under	FNC Entertainment
Total Training Duration	10 Years
Debut Year	2013
Key Milestone or Turning Point	Trained alongside Kwangjin

Jaehyun is N.Flying’s drummer who also trained for 10 years at FNC Entertainment. He started at FNC in 2003 at age 13, the same year as Kwangjin. 

For a full decade, he spent his time learning drums and getting better. While other kids his age were living normal lives, he was chasing his dream. His hard work paid off when N.Flying finally debuted in 2013.

10. Johnny – NCT 127

Joined as Trainee (Year / Age)	2007 (Age 13)
Agencies Trained Under	SM Entertainment
Total Training Duration	9 Years
Debut Year	2016
Key Milestone or Turning Point	Trained with EXO members

Johnny is an NCT 127 member who trained for 9 years at SM Entertainment. He joined SM in 2007 at age 13, moving all the way from Chicago to Korea. 

He trained alongside guys who would later become EXO. Can you imagine watching your friends’ debut while you’re still waiting? Despite that pain, Johnny stayed committed and finally debuted with NCT 127 in 2016.

11. Xiyeon – Former PRISTIN

Joined as Trainee (Year / Age)	2008 (Age 9)
Agencies Trained Under	Pledis Entertainment
Total Training Duration	9 Years
Debut Year	2017
Key Milestone or Turning Point	Joined Pledis as a child

Xiyeon was a PRISTIN member who spent 9 years training at Pledis Entertainment. She became a trainee in 2008 when she was only 9 years old, still in fourth grade. 

She spent almost her entire childhood and teenage years preparing. After nine years, she finally debuted with PRISTIN in 2017. Sadly, the group later disbanded, but her years of training showed real dedication.

12. Jinho – PENTAGON

Joined as Trainee (Year / Age)	2005 (Age 13)
Agencies Trained Under	SM Entertainment, Cube Entertainment
Total Training Duration	8 Years
Debut Year	2016
Key Milestone or Turning Point	Brief SM The Ballad debut before PENTAGON

Jinho is a PENTAGON member and soloist whose training lasted 8 years across two major companies. He trained at SM from 2005 and even debuted with SM The Ballad in 2010. But he wasn’t happy with just that. 

He moved to Cube Entertainment for more training and a fresh start. He finally re-debuted with PENTAGON in 2016, showing everyone his amazing vocals were worth the wait.

13. Moonbin – ASTRO

Joined as Trainee (Year / Age)	2006 (Age 9)
Agencies Trained Under	Fantagio
Total Training Duration	8 Years
Debut Year	2016
Key Milestone or Turning Point	First-ever Fantagio trainee

Moonbin was an ASTRO member who trained for 8 years at Fantagio. He joined in fifth grade in 2006 as their very first trainee. 

For eight years, he trained while also working as a child actor to support himself. He finally debuted with ASTRO in 2016 and became loved by many fans. We lost him in 2023, but his memory and hard work will always be remembered.

14. Bang Chan – Stray Kids

Joined as Trainee (Year / Age)	2010 (Age 13)
Agencies Trained Under	JYP Entertainment
Total Training Duration	7–8 Years
Debut Year	2018
Key Milestone or Turning Point	Survived to lead Stray Kids

Bang Chan is the leader of Stray Kids, who debuted on March 25, 2018. He moved from Australia to Korea in 2010 at age 13 and trained for almost 8 years. 

As one of JYP’s longest trainees, he faced a lot of pressure and doubt. But he didn’t give up. He later formed and led Stray Kids through their pre-debut survival show, turning his pain into power.

15. Seulgi – Red Velvet

Joined as Trainee (Year / Age)	2007 (Age 13)
Agencies Trained Under	SM Entertainment
Total Training Duration	7 Years
Debut Year	2014
Key Milestone or Turning Point	Known as SM’s “Ace” trainee

Seulgi is currently one of the best Kpop dancers and a Red Velvet member who trained for 7 years at SM Entertainment. 

She joined SM in 2007 at age 13 and became known as the company’s “Ace” trainee for her exceptional skills in dance, vocals, and performance. 

After seven years of hard work, she debuted with Red Velvet in 2014 and proved why she earned the “Ace” title.

Conclusion: G.Soul has the Longest K-pop training period for almost 15 years

G.Soul’s 15-year training period is still the longest verified in K-pop history. Moon Sua’s 12 years and G-Dragon’s 11 years come close behind. These numbers show the tough reality behind K-pop’s shiny surface. 

Most trainees debut within 3-5 years or give up. But these 15 idols proved that holding on can turn years of pain into lifetime success. 

Their stories remind us that a debut isn’t promised, but giving everything you have can make you a legend. Was it worth it? Their current success speaks for itself.

Also Read:

• Best K-Pop Visual
• Fastest Rappers In K-Pop
• Richest K-Pop Idols

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