Rythem (リズム, Rizumu?) was a Japanese Pop/Singer-songwriter duo consisting of two female members, Yui Nītsu (新津 由衣, Nītsu Yui?, born August 17, 1985) and Yukari Katō (加藤 有加利, Katō Yukari?, born April 3, 1985). They are signed to Sony Music Japan. In addition to their vocals, Yui plays the piano while Yuka plays the guitar. Rythem is notable for flowing, fluid harmonies and cheerful, upbeat melodies.