Daniel was born as Kang Euigeon (강의건) on December 10, 1996 in the coastal city of Busan as the only child of his family. After spending his childhood up to adolescence with his birth name, he later decided to legally change his name due to his family and friends having difficulties pronouncing Euigeon, thus adopting his current name Daniel, with a biblical hero as the source of his inspiration.
During Daniel’s childhood, his family went through financial problems after a business his father ran failed, and they were forced to move into a basement for a week. On the March 22, 2018 episode of MBC’s show Radio Star, Daniel was asked about his habit of smelling things. He revealed he had a trauma from the time he lived in that basement commenting, “The bathroom was right next to the room. The smell of mold and sewer was disgusting, and I smelled it while eating. I became sensitive to smells after that.” Some time later his parents divorced, and Daniel was raised by his mother on her own.
Although dancing is currently his passion, Daniel actually started dancing as a medium for self-healing. On September 4, 2017 during an appearance on KBS Hello Counselor, Daniel revealed that he was bullied in middle school due to his looks. It was then when his teacher suggested he start dancing, and this became a medium for him to cope with the problem and build his self-esteem. In KBS Sketchbook, he shared joining the b-boy club also happened by coincidence since he was planning to join the magic or reading club but missed the opportunity to sign up due to falling asleep. To pursue his passion in dancing, Daniel attended Peniel International High School of the Arts where he majored in modern dance and also Nataraja Academy (나타라자 아카데미), a dance academy in Busan. As a teenager, he was also active in the b-boying community in his hometown and used to perform under the name FLAC.