1THE9 – also known as 원더나인 (Wonder Nine) – burst onto the K-pop scene in 2019 as one of the most exciting project boy groups to come out of a Korean survival show. Whether you’re a longtime fan who’s been with Wonderland (that’s the official fandom name!) since day one, or a curious newcomer just discovering the magic of this nine-member crew, you’re in the right place.
We’re covering everything you need to know about 1THE9 – from their band history and member profiles to their discography, music videos, achievements, and live performance history. We’ll even break down fun facts for all nine members, so you can find your bias in no time.
Let’s dive right in!
Band Information
1THE9 is a South Korean boy band that was formed through the MBC survival competition show Under Nineteen in 2018. The group’s name is stylized as “1THE9” but is officially pronounced “Wonder Nine” – a nod to their nine members and their one-of-a-kind talent.
- Official Group Name: 1THE9 (stylized) / 원더나인 (Korean)
- Pronunciation: Wonder Nine
- Origin: Seoul, South Korea
- Genre: K-pop
- Number of Members: 9
- Label: MBK Entertainment / PocketDol Studio
- Formed Through: Under Nineteen – MBC survival reality show (2018)
- Official Debut Date: April 13, 2019
- Debut Album: XIX
- Debut Title Track: “Spotlight”
- Pre-Debut Single: “Domino” (ft. Crush) – released April 7, 2019
- Official Fandom Name: Wonderland
- Official Fan Color: Lime Punch
- Contract Type: 18-month project group contract (originally 17 months, extended due to COVID-19)
- Disbandment Date: August 8, 2020
- Final Album: Good Bye 1THE9 (August 5, 2020)
- Social Media: @official__1the9 (Instagram & Twitter)
- YouTube Channel: PocketDol Studio
- Member Selection: Top 9 contestants chosen by public vote during the live finale of Under Nineteen on February 9, 2019
- Team Breakdown: 3 members from Team Vocal, 3 from Team Performance, 3 from Team Rap
The 1THE9 Member Profiles
One of the best things about 1THE9 is how each member brings something totally different to the group. From powerhouse main vocalists to high-energy main dancers and sharp lead rappers, there’s a member for every K-pop fan to love. Let’s meet the whole crew!
| # | Stage Name | Full Name | Birthday | Position | Height | Blood Type |
|---|---|---|---|---|---|---|
| 1 | Yongha | Yoo Yong-ha (유용하) | Jan 11, 1999 | Leader, Sub Rapper, Vocalist | 177 cm (5’10”) | A |
| 2 | Taewoo | Kim Tae-woo (김태우) | Apr 23, 1999 | Lead Vocalist | 174 cm (5’9″) | – |
| 3 | Seunghwan | Lee Seung-hwan (이승환) | May 20, 2000 | Main Dancer, Lead Vocalist | 180 cm (5’11”) | – |
| 4 | Yechan | Shin Ye-chan (신예찬) | May 14, 2001 | Main Vocalist | 183 cm (6’0″) | – |
| 5 | Junseo | Kim Jun-seo (김준서) | Nov 20, 2001 | Lead Dancer, Sub Vocalist | 180 cm (5’11”) | – |
| 6 | Doyum | Jeon Do-yum (전도윤) | Feb 21, 2002 | Center, Main Dancer, Sub Rapper | 178 cm (5’10”) | – |
| 7 | Jinsung | Jung Jin-sung (정진성) | Mar 30, 2002 | Lead Vocalist, Lead Dancer | 176 cm (5’9″) | – |
| 8 | Taekhyeon | Jeong Taek-hyeon (정택현) | Jul 28, 2003 | Lead Rapper | 178 cm (5’10”) | B |
| 9 | Sungwon | Park Sung-won (박성원) | Dec 18, 2003 | Main Rapper | 178 cm (5’10”) | – |
💡 Did you know? The tallest member is Yechan at 183 cm (6’0″), while the shortest is Taewoo at 174 cm (5’9″). The leader and oldest member is Yongha (born 1999), and the youngest (maknae) is Sungwon (born 2003).
Yongha (Yoo Yong-ha)
Position: Leader, Sub Rapper, Vocalist | Under Nineteen Rank: 6th
Yongha
- Stage Name: Yongha (용하)
- Birth Name: Yoo Yong Ha (유용하)
- Probable Position: Leader, Lead Rapper, Vocalist
- Birthday: January 11, 1999
- Zodiac Sign: Capricorn
- Chinese Zodiac: Rabbit
- Height: 177 cm (5’10”)
- Weight: 64 kg (141 lbs)
- Blood Type: A
- Nationality: Korean
- Instagram: @you_haaaaa
He was born in Hwasun-gun, South Jeolla Province, South Korea – not Seoul!
His nickname is “Yong-Ddaengi,” which fans absolutely love.
He has an older sister born in 1995, making him the younger sibling.
He auditioned for the survival show The Unit but didn’t make the cut – his loss turned into 1THE9’s gain!
He was part of a busking group called Liberty with former Road Boyz members Jaehwan and Minsuk before his idol days.
On Weekly Idol (Episode 403), he introduced himself as “1THE9’s leader, anchor, and central figure” – no shortage of confidence there!
He was ranked 11th in fashion among all 19 trainees in Episode 13 of Under Nineteen.
He’s right-handed and a Capricorn.
He was part of Oui Boyz under the stage name “Youha” before joining WEi.
After 1THE9 disbanded, he debuted as a member of the WEi boy group on October 5, 2020, alongside fellow member Junseo.
Taewoo (Kim Tae-woo)
Position: Lead Vocalist | Zodiac Sign: Taurus
Taewoo
- Stage Name: Taewoo (태우)
- Birth Name: Kim Tae Woo (김태우)
- Probable Position: Vocalist, Rapper
- Birthday: April 23, 1999
- Zodiac Sign: Taurus
- Chinese Zodiac: Rabbit
- Height: 174 cm (5’8.5″)
- Weight: 62 kg (137 lbs)
- Blood Type: O
- Nationality: Korean
He’s the shortest member of 1THE9 at 174 cm – but his voice more than makes up for it!
He’s one of three members who came from the Team Vocal track on Under Nineteen.
He joined BLANK2Y after 1THE9’s disbandment, debuting with the group on May 24, 2022.
He’s known for having an incredibly warm and smooth vocal tone that fans fell in love with instantly.
Taewoo is a natural at harmony – he often provided the background harmonies in 1THE9’s biggest tracks.
He had the cutest habit of going all-out during group photo shoots, always making sure everyone looked great.
He was very close to Taekhyeon during their time together in the group.
Fans often described his stage presence as “quietly powerful” – he didn’t need to shout to be noticed.
He was born in spring (April), making him one of the group’s “spring babies.”
His warm, approachable personality made him a fan favorite off-stage as much as on it.
Seunghwan (Lee Seung-hwan)
Position: Main Dancer, Lead Vocalist | Zodiac Sign: Gemini
Seunghwan
- Stage Name: Seunghwan (승환)
- Birth Name: Lee Seung Hwan (이승환)
- Probable Position: Lead Dancer, Lead Vocalist
- Birthday: May 20, 2000
- Zodiac Sign: Taurus
- Chinese Zodiac: Dragon
- Height: 178 cm (5’10”)
- Weight: 66 kg (145 lbs)
- Blood Type: B
As Main Dancer, Seunghwan was one of the most visually captivating performers on stage during 1THE9’s run.
He was part of the Team Performance track on Under Nineteen, which focused on dance and stage presence.
He shared a room with Yongha and Jinsung during their training days – imagine those late-night conversations!
After 1THE9 disbanded, he participated in the survival shows LOUD and Boys Planet.
He made his solo debut on September 9, 2023 – a milestone moment for every Wonderland fan.
He left PlayM BOYS after his contract expired and chose to forge his own path in the industry.
His dance skills were so sharp that he often led the point choreography in group performances.
He was one of the members who kept in touch with fans consistently even after the disbandment.
Fans often picked his dancing in the “Turn Over” era as some of the best K-pop choreography of 2020.
He’s a Gemini – which fans say perfectly explains his ability to switch between powerful dance and gentle vocals.
Yechan (Shin Ye-chan)
Position: Main Vocalist | Zodiac Sign: Taurus
Yechan
- Stage Name: Yechan (예찬)
- Birth Name: Shin Ye Chan (신예찬)
- Probable Position: Main Vocalist, Lead Dancer
- Birthday: May 14, 2001
- Zodiac Sign: Taurus
- Chinese Zodiac: Snake
- Height: 183 cm (6’0″)
- Weight: 64 kg (141 lbs)
- Blood Type: A
- Nationality: Korean
Yechan is the tallest member of 1THE9 at an impressive 183 cm (6’0″).
As the Main Vocalist, he carried some of the most emotionally powerful moments in the group’s discography.
He debuted as a member of OMEGA X on June 30, 2021, continuing his K-pop journey after 1THE9.
He was famously ranked very highly on Under Nineteen – a testament to how much fans adored his voice.
He has one of the most distinctive vocal tones in the second-generation and third-generation K-pop crossover era.
His ability to convey deep emotion through singing made “Blah Blah” and “Turn Over” extra special.
He was one of the members fans most commonly cited as their “bias” due to both his talent and visuals.
He has always been passionate about music composition and hopes to participate in songwriting in future projects.
Fellow members often praised him as one of the hardest workers in the practice room.
After OMEGA X, he has been active as a solo artist – and Wonderland fans have been cheering him on every step of the way.
Junseo (Kim Jun-seo)
Position: Lead Dancer, Sub Vocalist | Zodiac Sign: Scorpio
Junseo
- Stage Name: Junseo (준서)
- Birth Name: Kim Jun Seo (김준서)
- Probable Position: Lead Vocalist, Lead Dancer, Rapper, Visual
- Birthday: November 20, 2001
- Zodiac Sign: Scorpio
- Chinese Zodiac: Snake
- Height: 178 cm (5’10”)
- Weight: 64 kg (141 lbs)
- Blood Type: O
- Nationality: Korean
- Instagram: @__k_junseo
Junseo was part of the Team Performance track on Under Nineteen, and his dancing skills are truly next-level.
He debuted as a member of WEi on October 5, 2020, alongside Yongha.
He later participated in the survival show Boys II Planet – giving fans even more content to enjoy!
He ranked 8th overall on Boys II Planet, which earned him a spot in the project boy group ALPHA DRIVE ONE.
ALPHA DRIVE ONE made their debut with the mini album Euphoria on January 12, 2026.
Despite being a Sub Vocalist, his tone added a beautiful color to 1THE9’s group harmonies.
He’s known for his extremely precise and controlled dance technique – every move is intentional.
Fans consistently ranked him as one of the best dancers not just in 1THE9 but in his entire Under Nineteen cohort.
He has always been described as a perfectionist by fellow members – he doesn’t rest until the performance is just right.
His journey from 1THE9 to WEi to ALPHA DRIVE ONE shows just how resilient and dedicated he is to his craft.
Doyum (Jeon Do-yum)
Position: Center, Main Dancer, Sub Rapper | Zodiac Sign: Pisces
Doyum
- Stage Name: Doyum (도염)
- Birth Name: Jeon Do Yum (전도염)
- Probable Position: Main Dancer, Lead Rapper, Vocalist, Center
- Birthday: February 21, 2002
- Zodiac Sign: Pisces
- Chinese Zodiac: Horse
- Height: 174.5 cm (5’8″)
- Weight: 55 kg (121 lbs)
- Blood Type: B
- Nationality: Korean
As the official Center of 1THE9, Doyum was often the visual focal point of their performances and music videos.
He was also the Main Dancer, meaning he had to master both charisma and technical precision simultaneously.
He shared a room with Jinsung and Seunghwan – the performance powerhouse trio!
After 1THE9’s disbandment, he debuted as a member of JUST B on June 30, 2021.
He’s a Pisces, and fans say his dreamy, artistic energy fits the sign perfectly.
He used to scold members on behalf of leader Yongha – because Yongha was “too kind to scold them” himself.
He introduced himself as “1THE9’s cutest, sexiest, and bubbliest member” on Weekly Idol – and nobody argued!
He’s extremely sentimental and was one of the members most visibly emotional about the group’s disbandment.
His favorite songs at the time of 1THE9’s run included Chet Baker’s “But Not For Me” and “Blue Room” – showing off his sophisticated music taste.
He’s good at aegyo (cute behavior) and was known for his very expressive, big reactions during variety show appearances.
Jinsung (Jung Jin-sung)
Position: Lead Vocalist, Lead Dancer | Zodiac Sign: Aries
Jinsung
- Stage Name: Jinsung (진성)
- Birth Name: Jung Jin Sung (정진성)
- Probable Position: Main Vocalist, Lead Dancer, Visual
- Birthday: March 30, 2002
- Zodiac Sign: Aries
- Chinese Zodiac: Horse
- Height: 176.5 cm (5’9″)
- Weight: 59 kg (129 lbs)
- Blood Type: B
- Nationality: Korean
- Instagram: dontxallmea
Jinsung holds a dual position as both Lead Vocalist and Lead Dancer – a rare and impressive combination.
He shared a room with Yongha and Seunghwan during group activities.
He was part of the Team Vocal track on Under Nineteen despite also being a skilled dancer.
He left PlayM BOYS after his contract ended and stepped away from the mainstream K-pop idol path.
He’s known for having a very warm, genuine personality that earned him deep affection from Wonderland fans.
During the “Blah Blah” era, his stage charisma was widely praised in fan reviews and community posts.
His ability to handle both singing and dancing at a lead level made him one of the most versatile members of 1THE9.
He’s an Aries – and fans say his fierce, energetic stage presence perfectly reflects that fire sign energy.
Fans still frequently tag him in nostalgia posts about 1THE9’s best live performances.
Even after the disbandment, he has maintained a quietly dedicated fan base who follow his updates closely.
Taekhyeon (Jeong Taek-hyeon)
Position: Lead Rapper | Zodiac Sign: Leo | Blood Type: B
Taekhyeon
- Stage Name: Taekhyeon (택현)
- Birth Name: Jung Taek Hyeon (정택현)
- Probable Position: Main Rapper, Vocalist, Face of the group
- Birthday: July 28, 2003
- Zodiac Sign: Leo
- Chinese Zodiac: Sheep
- Height: 178 cm (5’10”)
- Weight: 66 kg (145 lbs)
- Blood Type: B
- Nationality: Korean
- Instagram: @th728
Taekhyeon is a Leo, and his bold, magnetic stage persona is everything you’d expect from that sign.
He was the “special MC” in Episode 10 of Under Nineteen – already showing off his hosting charm before debut.
He was ranked the 13th “Boni” on the Boni Hani show, adding variety experience to his resume.
After 1THE9 disbanded, he pivoted to focus on his acting career – and his fans have loved supporting this new chapter.
He introduced himself as “1THE9’s MC and 2nd maknae” on Weekly Idol Episode 403 – a title the youngest members apparently contested!
He never called Yongha “Hyung” (older brother/sir) even once since debut, despite Yongha being four years older – a legendary 1THE9 trivia fact!
He tends to treat members as if they’re younger than him, regardless of actual age – a very Leo move.
He prefers cats over dogs and rings over necklaces – details that fans have memorized with devotion.
He chose Weekly Idol as the show he most wanted to appear on among all MBC programs.
His rapping style was sharp and precise – a great complement to main rapper Sungwon’s more powerful delivery.
Sungwon (Park Sung-won)
Position: Main Rapper | Zodiac Sign: Sagittarius
Sungwon
- Stage Name: Sungwon (성원)
- Birth Name: Park Sung Won (박성원)
- Probable Position: Main Rapper, Vocalist, Maknae
- Birthday: December 18, 2003
- Zodiac Sign: Sagittarius
- Chinese Zodiac: Sheep
- Height: 180 cm (5’11”)
- Weight: 58 kg (127 lbs)
- Blood Type: B
- MBTI Type: B
- Nationality: Korean
- Instagram: @inmypurple__
Sungwon is the maknae (youngest member) of 1THE9, born December 18, 2003.
Despite being the youngest, he held the weighty position of Main Rapper – a role that demands both skill and confidence.
He debuted as a member of Ciipher on March 15, 2021, continuing his musical journey post-1THE9.
He made his solo debut on December 4, 2023 – a big moment for his career growth.
He was part of the Team Rap track on Under Nineteen, where his skills clearly impressed enough to land him in the top 9.
Being the youngest didn’t stop him from commanding the stage – his rap presence was full of energy and grit.
Fans loved how he grew visibly as an artist during 1THE9’s short but impactful run.
He used the stage name “Won” during parts of the group’s promotional activities.
His Sagittarius spirit shines through in his adventurous approach to different musical styles.
Even as a teenager when 1THE9 debuted, his rap technique was polished enough to hold his own alongside older members.
Achievements
Even though 1THE9 was a project group with a limited contract, they packed an impressive list of accomplishments into their short time together. Here’s what they pulled off as a group:
| Achievement | Details |
|---|---|
| 🏆 Chart Success – Debut EP | Debut mini-album XIX peaked at #7 on the Korean music charts – a remarkable debut ranking. |
| 🏆 Pre-Debut Buzz | Pre-debut single “Domino” (ft. Crush) generated major excitement even before they officially debuted. |
| 🏆 Massive Fan Following | Built the dedicated Wonderland fandom with official fan color Lime Punch – a unique identity that stood out in the K-pop world. |
| 🏆 Multiple Successful Mini-Albums | Released 4 mini-albums (XIX, Blah Blah, Turn Over, Good Bye 1THE9) in just 16 months. |
| 🏆 TV Show Appearances | Appeared on multiple K-pop music shows, variety programs including Weekly Idol, and Vlive broadcasts. |
| 🏆 “Blah Blah” Chart Success | Second mini-album Blah Blah peaked at #15 on the South Korean charts, showing continued growth. |
| 🏆 Survival Show Legacy | Directly inspired by and formed through Under Nineteen, which had 57 contestants competing for 9 spots – making their debut even more meaningful. |
| 🏆 Post-Group Impact | All 9 members went on to successful follow-up careers in K-pop, acting, or solo music – a rare achievement for a project group. |
| 🏆 Fan-Selected Lineup | Their final lineup was entirely chosen by public audience vote during a live TV finale – making their connection to fans uniquely authentic. |
Discography and Music Videos
1THE9’s discography may be compact, but every release meant something. Let’s walk through their full catalog – from their exciting pre-debut single to their heartfelt farewell album.
📀 Complete 1THE9 Discography
| # | Title | Type | Release Date | Title Track | Chart Position |
|---|---|---|---|---|---|
| 1 | Domino | Pre-Debut Single | April 7, 2019 | “Domino” (ft. Crush) | – |
| 2 | XIX | Mini-Album (EP) | April 13, 2019 | “Spotlight” | #7 (Korea) |
| 3 | Blah Blah | Mini-Album (EP) | October 17, 2019 | “Blah Blah” / “속삭여” | #15 (Korea) |
| 4 | Turn Over | Mini-Album (EP) | July 16, 2020 | “Turn Over” | – |
| 5 | Good Bye 1THE9 | Final Special Mini-Album | August 5, 2020 | “Count” | – |
🎵 Album Highlights
Domino (Pre-Debut Single – 2019) Before their official debut, 1THE9 dropped “Domino” – a track written and produced by Under Nineteen‘s vocal trainer, Crush. It set the tone perfectly: cool, confident, and hook-heavy.
XIX (Debut Mini-Album – April 2019) The debut EP that started it all. “Spotlight” was the title track, and it lived up to its name – all eyes were on 1THE9. This album peaked at #7 on Korean charts, which was an exceptional performance for a project group’s debut.
Blah Blah (Second Mini-Album – October 2019) Their comeback showed real growth. Tracks like “Blah Blah” (속삭여) showed the group experimenting with sound and expanding their musical identity.
Turn Over (Third Mini-Album – July 2020) Coming out amid the COVID-19 pandemic, this album was a testament to the group’s resilience. This release was actually delayed due to the pandemic, which also pushed back their original disbandment date.
Good Bye 1THE9 (Final Album – August 2020) Probably the most emotionally charged release in their catalog. This special mini-album included reworked versions of fan-favorite tracks and the new title “Count.” It was described as a final gift to the Wonderland fandom before the group officially parted ways on August 8, 2020. Tracklist: “Count,” “Go Tomorrow (1THE9 ver.),” “We Are Young (1THE9 ver.),” “Friends (1THE9 ver.),” and “Count (Instr.)”
🎬 Notable Music Videos
- “Domino” – their punchy, visually stylish pre-debut MV
- “Spotlight” – the debut MV that introduced the world to all 9 members
- “Blah Blah” – showcased the group’s evolving choreography and aesthetics
- “Turn Over” – high-energy comeback MV with impressive group synchronization
- “Count” – the farewell MV, an emotional send-off that still moves fans to this day
Live Performances and World Tours
1THE9 officially disbanded in August 2020, so the group itself has no scheduled tours or live performances in 2026. However, their legacy lives on through the solo activities and group projects of each former member. Here’s a full breakdown of their live performance history during their active years, along with relevant 2026 updates on former members’ activities.
🎤 1THE9 Live Performance & Promotions Timeline
| Event / Show | Type | Year | Notes |
|---|---|---|---|
| Under Nineteen Final Concert | Pre-Debut Performance | Feb 23, 2019 | Performed with all Under 19 contestants |
| MBC Show! Music Core | Pre-Debut TV Performance | Feb 16, 2019 | Performed “Like a Magic” with final lineup |
| Debut Showcase (V Live) | Debut Showcase | Apr 17, 2019 | Announced fandom name “Wonderland” and fan color “Lime Punch” |
| Weekly Idol (Episode 403) | Variety Show Appearance | 2019 | Members introduced themselves with memorable self-introductions |
| Boni Hani | TV Variety / Performance | 2019 | Taekhyeon appeared as special MC |
| XIX Promotions – Music Shows | Music Show Circuit | Apr–May 2019 | Promoted “Spotlight” on Korea’s major music shows |
| Blah Blah Promotions | Music Show Circuit | Oct–Nov 2019 | Promoted comeback title track |
| Turn Over Promotions | Music Show Circuit | Jul 2020 | Final comeback stage promotions |
| Good Bye 1THE9 Final Promotions | Farewell Performances | Aug 2020 | Final performances before disbandment |
| Group Disbandment | – | Aug 8, 2020 | Official end of 1THE9 as a group |
🗓️ Former 1THE9 Members’ 2026 Activities
While 1THE9 as a group is no longer active, here’s what their former members are up to in 2026:
| Member | Current Group / Activity | 2026 Update |
|---|---|---|
| Yongha | WEi (OUI Entertainment) | Active with WEi |
| Taewoo | BLANK2Y | Active with BLANK2Y |
| Seunghwan | Solo Artist | Released solo music; continuing promotions |
| Yechan | OMEGA X / Solo | Solo artist activities ongoing |
| Junseo | ALPHA DRIVE ONE | Debuted with Euphoria on January 12, 2026 |
| Doyum | JUST B | Active with JUST B |
| Jinsung | Independent / Solo | Pursuing independent music activities |
| Taekhyeon | Actor / Solo | Focusing on acting career and solo projects |
| Sungwon | Solo Artist | Released solo debut December 2023; continuing activities |
💡 For Wonderland fans: While a 1THE9 reunion tour hasn’t been announced as of 2026, the K-pop world is always full of surprises. Keep your eyes on each member’s individual accounts – and remember, the nine of them clearly still hold a special place in K-pop history.
Final Thoughts
1THE9 might have only been together for about 16 months, but they made every moment count. From their chart-topping debut with XIX to their emotional farewell with Good Bye 1THE9, the Wonder Nine showed what true team spirit looks like. Each of the nine members – Yongha, Taewoo, Seunghwan, Yechan, Junseo, Doyum, Jinsung, Taekhyeon, and Sungwon – brought something irreplaceable to the group.
If you’re just discovering 1THE9 now, we genuinely envy you – you get to experience their full discography fresh. And if you’re a loyal Wonderland member who’s been here since the Under Nineteen days? You already know: once a Wonder Nine fan, always a Wonder Nine fan.