In 1945 she gave her first performance in a concert hall in Yokohama , at the age of eight . She used the name Kazue Misora , which her mother had proposed . He invested a small fortune taken from the family 's savings to begin a musical career for his daughter , and in 1945 she debuted at a concert hall in Yokohama , at the age of eight , as Kazue Misora , a name proposed by her mother .