What is the relationship of natural brother and sister

Brother and sister. The two siblings grew up in the freedom and music of the Southwest Miao Village, and in 2016, Yang Gang and his sister Yang Wenzi, who studied vocal music, formed the "Born Siblings" group and released "100% Good Man". Yang studied music in Beijing and released several singles, including "Guizhou, My Beloved Hometown", "Guizhou People Love Guizhou", "Your Mountains, Your Waters", "Mom and Dad", and "Lang at the Opposite Door to Pick the Water", etc. Among them, "One Hundred Percent Good Man" is the most popular song in China. Among them, "100% good man" after the launch of the audience harvested a lot of music reviews and fans praise, "Guizhou, my beloved hometown" network hits more than 300 million.