The lineup is established and the gentlemen had technically concluded their rookie year. Taking things into new territory, 24K tried their hand at the infamous "cute concept." Was it a success?

South Korean boy band 4K, the acoustic pop sub-unit of 24K, is a part of Choeun Entertainment. The sub-unit consisting of vocalists Cory (Korean: ?? [former member]), Seokjune (Korean: ?? [former member]), Kisu (Korean: ?? [former member]), and Sungoh (Korean: ??), released their debut EP Rocking Girl in June 2012. 

Participating in K-pop Star 2 brought friends Kim Hyo-Bin and Kim Il-Do together as a formal group called 2000Won (Korean: ???). Signed to Reve Entertainment (South Korea) since their debut in 2013, they formally came onto the scene with the support of established soloist Ailee the following year. Could this impressive duo be working on an upcoming project or was 2018's single the last we will hear from them?

Debuting in 2013 under SidusHQ, South Korean girl group 2EYES (Korean: ????) was designed to be the equivalent of their highly successful predecessors g.o.d. The short-lived girl group failed to produce a full album during their time together but set out to defy the usual girl group standards.

South Korean hip-hop duo 1Punch (Korean: ???) was formed by Brave Entertainment and debuted on January 23, 2015. Their lead single, "Turn Me Back" (???) came from their only album The Anthem. After their disbandment, One signed with YG Entertainment (eventually parting from the company after one project) and Punch, now entertaining under his name Samuel, gained notoriety in his own right. Both members debuted as solo artists in 2017.