2AM (Korean: 투에이엠) is a South Korean four-member ballad boy band under JYP Entertainment. The members are Jo Kwon, Jinwoon, Seulong, and Changmin. 2AM is one of the two subgroups branched out from the eleven-member (before Jaebeom's departure) boy band One Day, the other being 2PM. They officially debuted on July 11, 2008 on KBS's Music Bank, performing their debut 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.