Risa Niigaki is a Japanese actress and singer. She was a fifth-generation member of the Japanese pop group Morning Musume. She joined Morning Musume in 2001 along with 3 others- Ai Takahashi, Asami Konno and Makoto Ogawa. She grew up in Yokohama after moving there at the age of six. She was one of the longest serving members of Morning Musume, and was the leader of the group from October 2011 to her graduation on May 18, 2012.

Morning Musume '24 , formerly and commonly known as Morning Musume and colloquially referred to as Momusu , is a Japanese girl group, holding the second highest overall single sales on the Oricon charts as of February 2012, with the Oricon record of most top-ten singles, having 64 of them.