There are many things that K-pop fans can agree on and one of them is this: the concept of having sub-units is a godsend.
A sub-unit, in the world of K-pop, is a smaller group formed of a couple of members from the same K-pop group that produces music and content. These sub-units can be a duo, trio, or even more. Basically, it’s a K-pop group within a bigger group.
According to Soompi, K-pop agencies create sub-units in order to allow members to explore other concepts and to enrich their artistry and image. Which, to be honest, in the perspective of a K-pop fan, is a great avenue for K-pop idols to showcase more sides of them, as they can’t just be boxed in the concept that their original group is known for.
As such, here is a definitive list of K-pop sub-units that you should know of and listen to:
This sub-unit was the first of its time, being formed back in 2006. This group was formed by the legendary boy group’s main vocalists—Kyuhyun, Ryeowook, and Yesung. The trio had debuted with two songs, “The Night Chicago Died” and “The One I Love” for the K-Drama “Hyena.”
On June 8, 2020, the trio had released their first Korean EP, “When We Were Us”, as part of the celebrations of Super Junior’s 15th anniversary.
The fitfh sub-unit of Super Junior, composed of the group’s main dancers—Donghae and Eunhyuk. The duo debuted in 2011, with their digital single, “Oppa, Oppa,” and are currently one of the only sub-units of Super Junior active.
Super Junior D&E’s most recent release was their first Korean album, “Countdown,” which was released back on November 2, 2021.
Girls’ Generation TTS
Formed in the year 2012 following the girl group’s unannounced hiatus due to them focusing on individual activities, this sub-unit is Girls’ Generation’s first sub-unit. Composed by 3 members—Taeyeon, Tiffany, and Seohyun, the debuted with their first EP, “Twinkle.”
Their third EP was a Christmas special album titled, “Dear Santa”, where the members contributed a part of the album’s sales profits to the SM Ent.-UNICEF campaign charity, “Smile for U.”
Girls’ Generation- Oh!GG
This sub-unit is Girls’ Generation’s second unit, which are composed of the 5 members of SNSD who stayed with SM Entertainment—Taeyeon, Sunny, Hyoyeon, Yuri, and Yoona, and was formed in 2018.
Oh!GG has released one digital single titled, “Lil’ Touch,” along with their B-side track “Fermata” on September 5, 2018. The group was in hiatus until their participation in SMTown’s winter album, “2021 Winter SM Town: SMCU Express”, releasing the song “Melody.”
GD X TAEYANG
Though only officially releasing one single as a duo, BIG BANG’s GD x Taeyang’s debut track, “Good Boy,” has totally become a staple since its release. At the time of its release, “Good Boy” had reached the No. 1 spot on Billboard’s World Digital Songs, the third Korean act to do so following PSY and 2NE1.
After School’s first sub-unit was formed by third generation After School members Nana, Raina, and Lizzy. The trio debuted in December 2010 with the single, “Magic Girl.” The sub-unit went on to achieve mainstream success with their consecutive releases after their debut single.
Their most iconic track was their sixth overall single, “Catallena,” due to their “screaming” in the song’s introduction.
EXO’s first-ever sub-unit, it’s formed by members Chen, Baekhyun, and Xiumin back in 2016. Their first release as a trio was an OST for the K-Drama “Moon Lovers: Scarlet Heart Ryeo” titled, “For You.” Their debut as EXO’s first sub-unit wasn’t confirmed until October 5, 2016.
The trio then debuted officially with their EP, “Hey Mama!” and the title track of the same name. EXO-CBX has also released music in Japan, with their debut Japanese album titled, “Girls” was released on May 24, 2017.
EXO’s second sub-unit, formed by the group’s rappers Chanyeol and Sehun in 2019. Chanyeol and Sehun had first performed a song together during EXO’s concert tour, “EXO Planet 4 – The Elyxion” in 2018, titled “We Young,” which was later on released as part of the SM Station project on September 2018.
The duo later debuted in July 2019 with the EP, “What a Life.” EXO-SC later on won their first-ever music show win on KBS’ Music Bank ep on August 2, 2019—11 days after their debut. They had also released their first studio album in July 2020 titled, “1 Billion Views.”
Red Velvet – IRENE & SEULGI
(This unit was obviously made for the ladies).
Red Velvet – IRENE & SEULGI is the first sub-unit of Red Velvet, who debuted in July 2020 with their EP, “Monster”. Prior to the formation of Red Velvet, Irene and Seulgi had performed a cover of S.E.S.’s “Be Natural,” as members of SR14G (SM Rookies 2014 Girls), and was well-received by both the public and Lee Soo-man.
Their EP, “Monster,” consisted of six tracks with 2 singles, “Monster,” and “Naughty.” At the time, the duo was hailed as the “best selling female sub-unit” in South Korea in 2020. Red Velvet – IRENE & SEULGI also performed at the 2020 “Time 100 Talks,” where global leaders “talked about innovative solutions to urgent global problems,” and encouraged cross-disciplinary action” among its stakeholders.
This one’s a toughie. NCT’s entire concept is that there are 23 members, who are then divided into 4 different sub-units: NCT U (rotational), NCT 127, NCT DREAM, and WayV. A fifth sub-unit is currently under the works, but is currently known as NCT Tokyo.
NCT U, according to SM Entertainment, is a sub-unit that has rotational members that “fit the concept” that the song is asking for. The first NCT U unit composed of members Taeyong, Mark, Doyoung, Taeil, Ten, and Jaehyun,” who debuted with the digital singles, “The 7th Sense” and “Without You.” In NCT’s three full studio albums, “Empathy” (2018), “Resonance” (2020), and “Universe” (2021), there has been a wide variety of NCT U line-ups.
NCT 127 is NCT’s Seoul based sub-unit, with “127” representing the longitude coordinate of the city. The sub-unit’s original lineup consisted of Taeyong, Taeil, Yuta, Jaehyun, Winwin, Mark, and Haechan, who debuted in July 2016 with the EP “NCT #127.” Upon Jungwoo’s debut in 2018, he was added to NCT 127’s line-up.
NCT DREAM is NCT’s third sub-unit, originally planned as the group’s teenaged unit—complete with the admission and graduation system, until it had been abandoned in 2020. Consisting of members Mark, Renjun, Jeno, Haechan, Jaemin, Chenle, and Jisung, the septet debuted in August 2016 with the EP “Chewing Gum.”
WayV is NCT’s China-based unit, consisting of 7 members—Kun, Winwin, Ten, Lucas, Hendery, Xiaojun, and Yangyang, debuted in January 2019 with their single album, “The Vision.” In preparation for the unit’s debut, Winwin did not participate in NCT 127’s promotions for their first repackaged album, “Regulate.”
On February 24, 2023, SM Entertainment revealed that NCT’s “global expansion” concept will end with the debut of NCT Tokyo. On February 5, 2023, it had been announced that NCT is debuting a new fixed sub-unit named “DoJaeJung”—after members Doyoung, Jaehyun, and Jungwoo. They are set to make their debut in the first half of 2023.
LOONA 1/3, LOONA Odd Eye Circle, LOONA yyxy
Prior to LOONA’s official debut in 2018, the members of the girl group were announced through an 18-month long pre-debut project, beginning in 2016 which was called, “Girl of the Month.”
In March 2017, following the reveal of members HeeJin, HyunJin, Haseul, YeonJin, and ViVi (releasing her single album later) between Oct. 2016 and Jan. 2017, four members (excluding YeonJin) formed LOONA’s first sub-unit, “LOONA 1/3,” debuting with the EP, “Love & Live,” and later on the repackaged in April, “Love & Evil.”
In September 2017, after the reveal of members Kim Lip, JinSoul, and Choerry between May to July 207, they formed the sub-unit, “LOONA Odd Eye Circle,” and released the EP, “Mix & Match” and the single, “Girl Front.” In October of the same year, they released the repackaged version of “Mix & Match” with 3 new songs.
In May 2018, 2 months after the final revelation of the new members—Yves, Chuu, Go Won, and Olivia Hye, the third sub-unit named, “LOONA yyxy” debuted with their EP, “Beauty & the Beat.” Canadian musician Grimes featured in the sub-unit’s sub-unit, “love4eva.”
Also known as BooSeokSoon, is the first sub-unit of SEVENTEEN formed with the members DK, Hoshi, and Seungkwan back in 2018. The trio debuted with the single, “Just Do It” in March 2018. Later that year, they were nominated in the MAMA Awards under the “Best Unit” category.
BSS made their first comeback just recently with their first single album named, “Second Wind” last February 6, 2023, along with the title track, “Fighting” featuring rapper Lee Young-ji.
APink’s second sub-unit after Apink BnN back in 2014, ChoBom debuted in July 2022 and is formed by members Chorong and Bomi. The duo released their first single album titled, “Copycat.”
K-pop’s beloved “menage a trois”, Triple H was a unit formed by Cube Entertainment with soloist HyunA, and Pentagon members Hui and E’Dawn (now DAWN) back in 2017. The trio had released two EPs, “199X” (2017) and “Retro Futurism” (2018).
Triple H debuted in May 2017, with the EP “199X” and the single, “365 Fresh”. The album had reached 4th place on the Gaon Album Charts and 10th place on the Billboard World Albums chart of the time. In July 2018, the trio made their comeback with their second EP, “Retro Futurism” and the single, “Retro Future.”
Amid promotions, HyunA and DAWN were embroiled with dating rumors, to which the duo had confirmed in August 2018. Promotions for the sub-unit were cancelled, and CUBE Entertainment later announced that they will be terminating the contracts of HyunA and DAWN due to the inability to “maintain trust” with the two artists in September 2018.
HyunA and DAWN later on departed from CUBE Entertainment and signed with P Nation in 2019.
The only official sub-unit of former girl group PRISTIN, PRISTIN V debuted in May 2018 and was formed with members Nayoung, Roa, Eunwoo, Rena, and Kyulkyung. The sub-unit’s only EP was titled, “Like A V,” and the track “Get It” was the album’s lead single.
A year after, PLEDIS Entertainment announced the girl group’s disbandment following only 3 out of 10 members renewing their contracts with the agency.
Moonbin & Sanha
Members Moonbin & Sanha make up ASTRO’s first official sub-unit and debuted in September 2020 with their EP, “extended play” and the single, “Bad Idea.” A week after their debut, the sub-unit had already won their first music show win on SBS MTV’s “The Show.”
The duo has made 2 comebacks: in March 2022 with their second EP, “Refuge” and had released a pre-release single, “Ghost Town” and title track, “Who:,” and in January 2023 with their third EP, “Incense.”
DAY6 (Even of Day)
DAY6 (Even of Day) was formed in 2020 following the group hiatus of band DAY6 due to the mental health issues of some of its members. The band’s first sub-unit was formed with the remaining active members at the time: YoungK, Wonpil, and Dowoon.
The trio released their debut EP, “The Book of Us: Gluon” in August 2020, with the lead single, “Where the Sea Sleeps.” The EP was DAY6’s fourth chapter in their “The Book of Us” series. DAY6 (Even of Day) later on made their first comeback in July 2021 with the EP, “Right Through Me” and the title track of the same name.
Currently, the sub-unit is inactive due to the members all serving in the military, as per obligation in South Korea.
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