There are many sub units in kpop. There are sub units that are within the group, there are also which was created with different idol group members. In some cases there are sub units that are more popular than their group.

Whatever the case is, sub units have a sound that is different from their group.

Here are the list of sub units that definitely needs to happen:

Girl's Generation's Sooyoung, Hyoyeon and Yuri or as everybody knows SHY

These three have been hinting that they too want to make a sub unit. The fans just don't know what is stopping SM. These three will definitely bring the badass and chic concept back into style and trend if ever they will come true.

EXO's Baekhyun and DO

EXO fans and those who listen to their albums from the beginning know that these two fits RnB and Soul so much. If DO and Baekhyun will ever have a sub unit, they will definitely sing songs like "Baby Don't Cry" and it will be an all kill.

Zea's Kevin and UKISS Kevin

This is definitely a sub unit that nobody thinks of as they are from completely different group and agency. However, I think that they need something special like this for the fans to know them. I am thinking of a sexy guy to guy kind of Trouble Maker duo. I know fans would love that!

Red Velvet's Wendy and Blackpink's Rose

Red Velvet fans all know that Wendy is one of the talented idols today as she can play many instruments, same with Blackpink's Rose. I think it would be really awesome if they will make a sub unit and release acoustic songs. I would totally buy their album!

Just imagine the amazing songs and music that we will get from these sub units if ever it will happen.

Can you think of any other sub units that need to materialize?