Riyu Kosaka Kosaka Riyu) is a J-pop singer, as well as a member of the Konami-produced J-Pop group BeForU. Kosaka was born in Yokohama, Kanagawa, Japan on , 1985. On November 20, 2000, Konami and Toshiba-EMI staff held auditions to form a J-pop group, which would eventually become BeForU.
