Nagatomo Sayaka (長友さやか), better known by her stage name SAYAKA, is a Japanese performer. She is a member of the groups Happiness and E-girls.

She attended the dance school EXPG in Miyazaki, appearing at EXILE's events, in music videos and on tour as a background dancer. In the spring of 2008, it was decided that she would become a member of the unit Happiness among other EXPG students, and her official stage name became SAYAKA.