Lee Gi-kwang was born on March 30, 1990 in Naju, South Korea. Gi-kwang found interest in hip hop and had a particular liking to many classic hip hop acts. He was backed by his family to pursue a musical career and after auditioning for a record company debuted under the stage name 'AJ'. He was known as the solo singer AJ or Ace Junior when he first debuted and released a mini-album "First Episode: A New Hero” on April 4, 2009. He now goes by his original name, as he re-debuted with Beast. He debuted as an actor through High Kick Through the Roof and was also cast in the drama, My Princess. He also became an MC for different shows such as Hot Brothers, Win Win, and SBS Inkigayo.