CNBlue

I don't know this group even more than 2AM...
They're simply a rock band, consist of 4 people
They're Jung Yonghwa (leader, lead vocal, main rapper and rhythm guitar), Lee Jonghyun (lead guitar, vocals), Lee Jungshin (bass guitar, backing vocalist) and Kang Minhyuk (drums, backing vocalist)
"CN is an abbreviation of ‘Code Name’ while BLUE is an abbreviation of the members’ individual images," said by one of the members. ‘Burning’ represents Lee Jonghyun, ‘Lovely’ represents Kang Minhyuk, ‘Untouchable’ represents Lee Jungshin, and ‘Emotional’ represents Jung Yonghwa.