Sean was born Christopher Sean Friel on October 25, 1985, in Oak Harbor, Washington, to Patrick and Sayuri Friel. He has two sisters, Candis and Melody. While his family moved around a lot, Sean grew up mainly in Southern California. Sean is Japanese on his mother's side, and Irish, German and Spanish through his father. Sean grew up in the military because his father was in the Navy. When his father Patrick was stationed away from home, he would put himself on video reading books to Christopher and his sisters and their mother would send recordings of her children to her husband. Sean explained that he was always very comfortable in front of the camera and those experiences inspired him to get into acting. Growing up, Sean had a big poster of Bruce Lee on his wall and admits there weren't many people for him to relate to in the entertainment industry. Sean speaks Japanese, which he picked up from his parents when his father was assigned to the USS Tripoli. Sean is trained in boxing, Taekwondo, wrestling, Jujutsu and Mixed martial arts.