10 Of The Most Underrated Sub-Units In Kpop

South Korean music and entertainment is extremely vast and continuously growing! Every year there are new groups, solo artists, duos, projects, and collaborations. However, some people tend to forget about one particular method of continuing music trends: sub-units!

Bands, especially those with many members, group a portion of the members together for a separate project. Whether it’s due to some of the original band members not being active, wanting to gain more interest in the group as a whole, or simply wanting to try a new style outside of their band’s “norm,” these sub-units have proven incredibly popular in the past and present.

Newer fans would likely recognize popular sub-units such as EXO-CBX, GD and Taeyang, Taetiseo, and Block B Bastarz. However, some sub-units in the past and present haven’t seen quite as much recognition as others. Let’s check out 10 Kpop groups and some of their best sub-units many fans may not be familiar with!

*I’ll be focusing on sub-units made directly from an original band who went on to officially debut and promote. This does not include projects that mix people from more than one group (e.g. Troublemaker: Hyunseung and HyunaYTeen: Monsta X and WJSN), units that are part of a larger whole (e.g. NCT Dream and NCT127), collaborations, or temporary projects for concerts. I’ve also left out projects that were made prior to the current group (e.g. JJ Project of GOT7 and Bang and Zelo of B.A.P).


1- After School Blue and Red

As a girl group with an average of nine members at a time, it only makes sense there would be smaller sub-units to promote a somewhat different style. Orange Caramel was incredibly popular to the point where many people didn’t realize it was a sub-unit of the larger band, After School. Due to this, not many are familiar with the sub-units AS Blue (consisting of members Jooyeon, Raina, Lizzy, and E-Young)  and AS Red (consisting of members Kahi, Jungah, Uee and Nana). The two sub-units’ members were split up and decided by online votes from fans. They debuted within a week of each other and “battled” using two vastly different concepts.

2- Super Junior T, H, D&E, and K.R.Y

Super Junior M, the sub-group of Super Junior that promotes in Mandarin Chinese, is arguably the most popular and well-known sub-group of the band. However, there were four (yes, four!) more subgroups that emerged from Super Junior throughout the past years. K.R.Y is a ballad group consisting of main singers Kyuhyun, Ryeowook, and Yesung. Super Junior T is based around an older Korean music style called Trot and consists of  members Leeteuk, Kangin, Heechul, Sungmin, Eunhyuk, and Shindong. Super Junior H, otherwise known as Super Junior Happy, brightened the Kpop scene with hilarious and adorable antics and music. The line-up was made up of Leeteuk, Yesung, Kangin, Shindong, Sungmin, and Eunhyuk. Of course, I can’t forget the talented dancer-duo, Eunhyuk and Donghae, who make up Super Junior D&E. The duo promotes actively in both Korea and Japan, even holding their own Japanese tour. Super Junior M, K.R.Y, and D&E are still active to this day. In addition, Super Junior T recorded a new song for Super Junior’s last album, Magic.

3- T-ara N4

T-ara N4 is the only sub-unit of the band T-ara that consists of members Eunjung, Hyomin, and Jieun. With the original member Areum as well, they debuted the sub-unit in April of 2013 with the song “Jeon Won Diary.” The song was an incredible hit for the time and holds over 10 million views as of this year! The song is about getting away from the haters and harsh reality of every day life by going to relax in the countryside. It features former SPEED member and label-mate at the time, Taewoon.

4- ZE:A Five, 4U, and J

ZE:A (제국의 아이들), despite not releasing any albums since 2015, went through a stage of incredible popularity years ago. Sadly, none of the ZE:A sub-units have gathered much exposure over the years. Each sub-unit is actually more of a recent endeavor (in comparison to full band comebacks) in attempts to re-kindle interest among fans. ZE:A FIVE is made up of members Siwan, Hyungsik, Kevin, Minwoo & Dongjun. Their song “The Day Before We Broke Up” garnered a decent amount of attention and now boasts almost 2 million views. ZE:A 4U was a sub-unit made to promote in Japan and was made up of the remaining four members  of the group, Kwanghee, Lee Hoo, Taeheon & Heechul. ZE:A J was another sub-unit made to promote in Japan with a slightly different member set up from 4U and FIVE and included members Kevin, Taeheon, Heechul, Minwoo & Dongjun.

5- uBEAT

U-KISS was one of the most well-known bands internationally in the previous era of Kpop. Having debuted back in 2008, they’ve gained lots of experience through member solo projects, touring in multiple countries, trying various concepts, and leading through variety shows. However, they had only one sub-unit, uBEAT. The name is a play on words for the band name “U-KISS” and hip-hop “beats” since it is the endeavor of the two rappers at the time, Eli and AJ. They debuted with the song “Should Have Treated You Better” in April of 2013. Fellow member Kevin featured in the song for them as a singer. U-KISS has gone through many changes over recent years, including AJ going on hiatus to pursue school and then later leaving the group, Dongho and Eli being some of the first idols to openly get married and have children, and the very recent departure of Kevin.

6- 2YOON

4Minute is one of those timeless groups who never disappointed with comebacks. Back in 2013, vocalists Gayoon and Jiyoon created a duo. It was properly titled 2YOON, which combined the syllable they have in common in their names. What set them apart from others was certainly their debut song concept. Who knew Kpop could go country? With that banjo twang in the intro and a catchy beat that’ll make ya’ want to tap your shoes, “24/7” is that kind of song that easily gets stuck in your head. Members of BtoB featured in the music video, dancing and dressing in the western, cowboy style like Gayoon and Jiyoon. Sadly, the sub-unit never had a comeback before the group’s disbandment in 2016.

7- HIGH420

High4 debuted back in 2014 with a sweet, spring like concept. However, their first sub-unit, HIGH420, emerged in 2016. Having only four members in the band, the reason for creating a sub-unit had nothing to do with multiple people. Instead, it was the two rappers Youngjun and Alex who broke off to make their own rap-themed music that was far from the main group’s original style. The duo insisted the name was a combination of HIGH4 and their favorite age, 20. However, most fans realized it was a play on words for the term “420,” a slang phrase that has to do with marijuana use. The song they debuted with was called “HookGA,” and the lyrics boasted about themselves and talked about partying the night away. It featured MAMAMOO‘s Hwasa who gives her own impressive, unique rap in the song.

8- 100% V

Rockhyun, Jonghwan, Hyukjin, and Chanyong were the four members of Top Media‘s 100% who make up the sub-unit, 100% V. The original group debuted in 2012 – a busy year for K-pop debuts! Merely ten months later, it was announced that they would be creating a sub-unit with a style closer to that of ballads and OSTs. The beautiful song “Missing You” was paired with a drama-like music video and many fans were excited to see a different side of the group through the new unit. However, the sub-unit has yet to have a comeback due to member changes and decreasing activity/popularity.

9- Infinite F

Infinite! This seven-member Woollim Entertainment group has upheld a high level of popularity and activity since their debut back in 2010. Like many bands, this group is active in variety, reality, composition, and various music projects. Members Sunggyu and Woohyun have both gone on to have successful solo careers. Not to mention, Woohyun’s also had a collaborative duo with SHINee‘s Key called ToHeart. One of the group’s sub-unit Infinite H (Dongwoo and Hoya) has become well-known for their smooth, hip-hop, and R&B style. However, there’s one sub-group somewhat less known. The maknaes of the group were the only members who had yet to take on a separate music project within the band. Therefore, Sungyeol, L, and Sungjong banded together to make a trio sub-unit with a bright and refreshing sound. Infinite F debuted with the song “가슴이 뛴다 (Heartbeat)” in November of 2014.

10- Rainbow Blaxx

Rainbow is a seven-member girl group who debuted back in 2009. Four members of the group were put together to represent a more sexy and mature theme than what Rainbow fans were used to seeing. Rainbow Blaxx consisted of members Jaekyung, Woori, Seungah and Hyunyoung and was named such to represent the darker color not found in the rainbow. Their debut song “Cha Cha” took on a discothèque style and was a huge hit at the time of release. It currently sits at over 9 million views, beating out the record of a few of the original group’s videos. The music video was also well-received, as it casually brings up issues with body and beauty expectations for idols. They never had a comeback before the full band finally disbanded due to not renewing contracts in late 2016.

Sub-units are certainly a great way to spread the music we all know and love even more! Not to mention, it gives companies and idol members chances to expand their horizons and attempt new styles of music. There’s plenty of new groups and sub-units every year, and I look forward to experiencing them all!

Were there any sub-units on this list that you didn’t already know about? Which current bands do you hope will start a sub-unit in the future? Let us know in the comment section below!

CaptainMal has been into Korean Entertainment for seven years now, since 2010. She travels to conventions in her area, showcasing her “Kpop Game Show’” and occasional Kpop cosplay. Although her favorite bands are Infinite, Super Junior, and VIXX, she boasts a love for a huge variety of artists throughout the last 15 years of Kpop. Other than Kpop, CaptainMal loves Disney, 80’s rock, Daft Punk, Gaming, and Orange Juice.

Media: As credited

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