Ryu Sera (Korean: 류세라); born September 3, 1987), is a South Korean idol, singer, dancer, and model. She is the main vocalist of the South Korean girl group Nine Muses. She is one of the original line-up of Nine Muses and debuted with the group in August 2010. She was born in Toronto, Canada. She has one younger brother. She was the leader of the group for a while (after their previous leader Kim Rana decided to leave for individual activities and before it was decided that Nine Muses would have no leader). She won 3rd Place at 2005 Canada N/W Idol.