of Kim Donghyun, Shim Hyunseong, Lee Jeongmin, Jo Youngmin, Jo Kwangmin and No Minwoo. The group has released three Korean single albums. They debuted on  Mnet 's  M!Countdown  on May 26, 2011 with their debut single "Boyfriend". Their fanbase was officially named "Best Friend" as of August 10, 2011. Watch  Boyfriend