Seo Dahyun
서다현 (Seo Dahyun) · Real name: Seo Da-hyun · English nickname: Ruby Seo
Ruby Seo
January 8, 2003 South Korean 160.1 cm (5'3") Not officially confirmed Type A ISFP
Seo Dahyun is a South Korean singer and the tenth revealed member (S10) of tripleS, the 24-member girl group under MODHAUS known for its decentralized, fan-driven concept. Born on January 8, 2003, in Busan, Seo Dahyun trained for years before debuting, first as a Source Music trainee where she even sang backing vocals for GFriend, and later joining MODHAUS in 2022. She was officially unveiled as tripleS's tenth member in December 2022 and made her group debut with the EP Assemble in February 2023. Recognized as tripleS's main vocalist, Seo Dahyun is praised for her powerful yet emotional tone and impressive vocal range, qualities that led her to become the leader of the group's ballad-oriented sub-unit Aria. Beyond her main group activities, she is also part of the sub-units LOVElution and Neptune, and has lent her voice to Korean drama OSTs including "I'm In Love You" for Reborn Rich. With her representative color Lavender Rose and a warm, approachable image, Seo Dahyun continues to grow as one of tripleS's most vocally distinctive members, connecting with the group's fandom WAV through comebacks like Assemble24, Assemble25, and Beyond Beauty.
Story
Biography
Who Is Seo Dahyun of tripleS?
tripleS member Seo Dahyun is widely recognized as the group’s main vocalist, known for a powerful yet emotional tone that has made her one of the most talked-about vocal talents in fourth-generation K-pop. Born on January 8, 2003, in Busan, South Korea, Seo Dahyun spent years training before her debut, first under Source Music, where she quietly contributed backing vocals to GFriend’s song “Hope,” and later under MODHAUS, the agency behind tripleS’s ambitious decentralized idol concept.
Trainee Days and Debut
Seo Dahyun joined MODHAUS as a trainee in February 2022 and was officially unveiled as tripleS’s tenth member (S10) on December 3, 2022. She made her official group debut on February 13, 2023, when tripleS released its first EP, Assemble, led by the single “Rising.” From the start, her clear, expressive singing set her apart, and it wasn’t long before she took on leadership duties in one of the group’s most distinctive sub-units.
Leading Aria and Growing With tripleS
In January 2024, Seo Dahyun became the leader of Aria, tripleS’s ballad-focused sub-unit, debuting with the single album Structure of Sadness. A few months later, she joined all 23 other members for tripleS’s first studio album, Assemble24, marking the group’s historic debut as a complete 24-member act. She continued building her discography through Assemble25 in 2025 and joined the msnz sub-unit Neptune for the mini album Beyond Beauty that same year, before returning with the full group for LOVE&POP pt.1 in June 2026.
With her warm stage presence and consistently praised vocal ability, Seo Dahyun remains a standout member of tripleS and a favorite among the group’s fandom, WAV.
Profile
Basic Information
| Stage Name | Seo Dahyun |
| Full Birth Name | Seo Da-hyun (서다현) |
| Date of Birth | January 8, 2003 |
| Birthplace | Gwangan-dong, Suyeong-gu, Busan, South Korea |
| Hometown | Busan, South Korea |
| Nationality | South Korean |
| Height | 160.1 cm (5'3") |
| Weight | Not officially confirmed |
| Blood Type | A |
| Zodiac Sign | Capricorn |
| MBTI | ISFP |
| Education | Hanlim Multi Art School (Practical Music Department) |
| Agency | MODHAUS (formerly a trainee at Source Music) |
| Debut | February 13, 2023 (tripleS, EP Assemble) |
| Languages | Korean |
| Nicknames | Ruby Seo |
| Hobbies | Watching cat videos, sleeping in, ordering tteokbokki, going on walks alone |
| Favorite Color | Lavender Rose (representative color) |
| Ideal Type | Not officially confirmed |
Membership
Groups & Positions
tripleS
MODHAUS
Main Vocalist Leader of Aria Member of Neptune
2022 - Present
The Lineup
Group Members — tripleS
Yoon SeoYeon
Member
Jeong HyeRin
Member
Lee JiWoo
Member
Kim ChaeYeon
Member
Kim YooYeon
Leader of tripleS, Visual
Kim SooMin
Member
Kim NaKyoung
Dance Leader
Gong YuBin
Member
Kaede
Main Dancer, Main Vocalist
Seo DaHyun
Main Vocalist, Leader of Aria
This Idol
Kotone
Member
Kwak YeonJi
Member
Nien
Member
Park SoHyun
Member
Xinyu
Member
Mayu
Vocalist, Leader of ∞! (Hatchi)
Lynn
Main Dancer
JooBin
Member
Jeong HaYeon
Member
Park ShiOn
Member
Kim ChaeWon
Member
Sullin
Leader of Moon, Member of Glow
SeoAh
Maknae
JiYeon
Leader of Glow
Journey
Career Timeline
2022
Became a MODHAUS Trainee
Joined MODHAUS as a trainee in February 2022 after previously training at Source Music.
2022
Revealed as S10
Officially unveiled as tripleS's tenth member (S10) on December 3, 2022.
2023
Group Debut with Assemble
Made her official tripleS debut with the EP "Assemble" and lead single "Rising" on February 13, 2023.
2023
Sang Drama OST
Contributed the original soundtrack "I'm In Love You" for the Korean drama series Reborn Rich.
2024
Aria Sub-unit Debut
Debuted as the leader of tripleS's ballad-focused sub-unit Aria with the single album "Structure of Sadness" in January 2024.
2024
Full 24-Member Debut
Took part in tripleS's first studio album "Assemble24" and lead single "Girls Never Die" as part of the completed 24-member line-up on May 8, 2024.
2025
Assemble25 Comeback
Returned with tripleS's second studio album "Assemble25" and lead single "Are You Alive" on May 12, 2025.
2025
Neptune Sub-unit Debut
Joined the msnz sub-unit Neptune, debuting with the mini album "Beyond Beauty" on November 24, 2025.
2026
LOVE&POP pt.1 Comeback
Returned with the full 24-member group for the mini album "LOVE&POP pt.1" and title track "Baby Flower" on June 1, 2026.
Music
Discography
🎵
N/A
N/A
N/A
💜
Assemble
EP
2023
💜
Structure of Sadness (Aria)
Single Album
2024
💜
Assemble24
Studio Album
2024
💜
Assemble25
Studio Album
2025
💜
Beyond Beauty (Neptune)
Mini Album
2025
💜
LOVE&POP pt.1
Mini Album
2026
🎧
Rising
Digital Single
2023
🎧
Girls Never Die
Digital Single
2024
🎧
Are You Alive
Digital Single
2025
🎧
Baby Flower
Digital Single
2026
Recognition
Awards & Achievements
Best New Female Artist
MAMA Awards
2023
First Music Show Win ("Girls Never Die")
The Show
2024
Did You Know?
Trivia & Fun Facts ✨
★
Dahyun's full birth name is Seo Da-hyun (서다현).
★
She was born in Gwangan-dong, Suyeong-gu, Busan, South Korea.
★
She trained at Source Music before joining MODHAUS, and during that time sang chorus vocals for GFriend's song "Hope."
★
She has been a MODHAUS trainee since February 2022.
★
Dahyun sang the OST "I'm In Love You" for the Korean drama Reborn Rich.
★
She is close friends with former HOT ISSUE member Yebin.
★
In 2021, she appeared on the fourth episode of the blind dating show Sixth Sense.
★
She was officially revealed as tripleS's tenth member (S10) on December 3, 2022.
★
Dahyun attended Hanlim Multi Art School in the Department of Practical Music.
★
Hearing EXO's "Growl" around age 13 is what first got her interested in K-pop.
★
Two of her favorite meats are pork and beef.
★
She has been training since she was in ninth grade.
★
Her hobbies include watching cat videos, sleeping in, and ordering tteokbokki.
★
Dahyun's favorite characters are Kirby and Pachirisu.
★
Some of her favorite foods are meringue cookies, gyeran-jjim, tteokbokki, and chicken.
★
She once passed the second-round audition for Dreamcatcher Company (formerly Happyface Entertainment).
★
She previously used an Instagram account called @cherryphoria before deactivating it when she became a MODHAUS trainee.
★
She has a small mole on the right side of her neck.
★
Her English nickname among fans is "Ruby Seo."
★
Her representative color within tripleS is Lavender Rose.
★
She has named TAEYEON of Girls' Generation as one of her role models.
★
She is the leader of tripleS's ballad-oriented sub-unit Aria.
★
She is a member of the msnz sub-unit Neptune alongside SeoYeon, NaKyoung, Nien, Kotone, and SeoAh.
★
She is praised for her powerful yet emotional vocal tone and wide vocal range.
The Fandom
Fan Club & Fan Name 💜
Official Fan Name
WAV
WAV is the official fandom name of tripleS, representing the wave of support fans bring to the group's decentralized, fan-participation-driven concept.
Official Fan Color
Not officially confirmed
N/A
Official Light Stick
heartS
The official tripleS light stick, named heartS, was chosen by WAV through a Gravity fan-voting event and was first announced on May 21, 2024.
Fan Community Platform
Cosmo: The Origin
Cosmo is tripleS' official fan platform app where WAV members collect Como points by purchasing Objekt photocards, then use Como to vote in Gravity events that decide sub-unit lineups, concepts, and other group decisions.
Stay Connected
Social Media
Photos
Gallery 📷
