2AM

2AM is a four-member boy band from Seoul, South Korea under JYP Entertainment. The members are Jinwoon, Jokwon (the leader), 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 11 July 2008 on KBS's Music Bank, performing their debut song "이노래" (This Song)

Predebut

Along with the members of 2PM, 2AM appeared on the documentary Hot Blood that was aired on Mnet, documented their rigorous training program of 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. JoKwon trained for 2567 days, close to 7 years after joining JYPE. He holds the record as the trainee who trained the longest under JYPE.

Debut (2008)

2AM's first single "This Song" release 21 July 2008 and made their debut performance on 11-13 July 2008 performing their debut song "이노래"(This Song) which talks about a man who has nothing left to offer his love except for one song.

Comeback (2009)

2AM made a comeback with another single album "Time For Confession" on 19 March 2009 with "친구의 고백" (A Friend's Confession) being the title track. Their comeback stage was aired 20-23 March  2009.

credit: Wikipedia