[VINS (Voice in Soul) - Two Words]
Released a mini album with this song and another single 'Second Breakup' and that's all they seem to have done.
[4Minute - Hot Issue]
Constant fixture on the kpop scene until last year when Cube decided to only renew Hyuna's contract. Hyuna will probably continue to promote solo while the other members aren't as clear (I'm sure someone has more info than me..)
[E.via - Hey!]
Used to be knwon as Napper whiel she was an underground raper. 'Officially' debuted in 2009 under the name E.via. Released a number of albums up until 2012 when issues with her management caused her to change labels.
After changing labels she also changed her name to Tymee. She was part of Mnet's Unpretty Rapstar in 2015 and last released music only four months ago.
[Hong Jin Young - Love's Battery]
Used to be part of the group Swan (who only seem to have promoted one song). Debuted solo in 2009 and has promoted fairly consistenly since then. She stared in 50 episodes of season four We Got Married with virtual husband Nam Goong Min. She's probably one of the most known trot singers to foreign hallyu fans.
[St.Day - Afraid]
Released one mini album that contained this single. Hasn't actively promoted since then, but in 2014 he collaborated with a few singers on an OST song for the web drama 'The Best Future' [the drama stars Minah from Girl's Day and 5urpise's Seo Kang Joon].
[R.Tripper - Far Away]
Most known for this song that they debuted with. Appear to have continued to promote until the end of 2010. In 2011 member W.dop joined the ballad group M.Street (who were making their first comeback after the death of their lead singer in 2009).
Here is the R.Tripper's debut post on omona.
[Flying Girls - Girl's Hot]
Only ever released this song, they apparently were meant to have a collab with Miyro from BEG but that never happened. Park Sora became a STYLE NADA model (as of 2014, not sure if she still is), and Jisoo had some minor acting roles in 2009.
[T-ara - Lie]
Netizens love to hate them, and they continue to promote as a group as well as solo projects.
[Gilme - Love Cuts]
Steadily released single albums since her debut. She is also part of the hip-hop project group Clover. She was also part of Unpretty Rapstar 2 that aired in 2015.
[Honeysh - Shall I Get Married?]
Released this song plus a few other singles and an OST. Don't seem to have promoted past 2009.
They were criticized for the provcative nature of the MV for this song.
[TwiNy - Flutter]
Couldn't find much on them apart from one member had an unfortunate costume malfuntion that was luckily not broadcast. They didn't promote after this single.
[B2Y - Jeez!]
Released a mini album in 2009 and a single album in 2010 before disbanding in early 2011. The company CEO kicked the two female members for 'committing immoral acts'. One member had a minor role in Sungkyunkwan Scandal.
[f(x) - Lachata]
Although member Sulli left to 'focus on acting'; the band is still somewhat active, they have mostly been focusing on solo activities the past few years.
**Part 1 is HERE**
Sources: sment, MV Korea, CJENMMUSIC Official [x] [x] [x], 1theK, T-ARA Official, MiDeCo86, makinouri, DanalEntertainment, RHYTMER, 4MinuteVEVO,
Part 2 ~~ there is going to have to be at least another part OTL. So many 2009 debuts.