2AM (Korean: 투에이엠) is a South Korean boy group under JYP Entertainment, consisting of Jo Kwon, Lee Changmin, Lim Seulong and Jeong Jinwoon. It was one of the two subgroups split from the eleven-member boy band One Day, the other being 2PM. They officially debuted on July 11, 2008 on KBS's Music Bank, performing the song "This Song". They won their first Mutizen at Inkigayo on February 7, 2010 with "Can't Let You Go Even If I Die".
Along with the members of 2PM, 2AM appeared on the documentary Hot Blood that was aired on Mnet, documented their rigorous training program on their pre-debut days. Changmin was the only member of One Day to not appear in the documentary because he was serving in the military at that time. Initially, Jinwoon was eliminated on Hot Blood, but he ended up in 2AM due to Daehun's withdrawal from JYPE.