Biological. Lin Xichi and lin xi Geng are the characters in the TV series "The Best You in the World". They are brothers and sisters. Lin xi Chi is played by S. Ireine, and lin xi Geng is played by Chen Ze. The Best You in the World tells the story of Lin Xichi, a girl from a divorced family, and Xu Fang, a proud archer, who fell in love and killed each other since childhood.