The first member to join was Kim Junsu. At the age of 12 he was brought into SM Entertainment through a televised talent search with Moon Hee Jun and Kangta from H.O.T. as judges. His vocals won over the judges and procured him thorough training for the next six years. After three years of training, he was supposed to debut, but puberty caused his voice to change and he was unable to sing until it ended after another three years. After six years, he debuted as Xiah Junsu (Xiah is pronounced Shee-ah in Korean). Xiah is the stage name that Kim himself chose, explaining to his fans that the name was short for "Asia", as Asia is pronounced "ah-shee-ah" in Korean. "Xiah" would be an implication of his desire to become not only a star in Korea, but also a star recognized all throughout the continent.
Image credits: as tagged