Ruby is the daughter of Summer Rose and Taiyang Xiao Long, as well as the younger half-sister of Yang Xiao Long, with whom she was raised on the island of Patch. When she was very young, Yang would read her fairy tales every night before bed, filled with the deeds of great heroes; this would later inspire Ruby to become a Huntress. One day, Summer went missing while on a mission. Yang said that, although Ruby was "really torn up" by the incident, she was too young to really understand what was happening.