Mari Yaguchi (矢口真里, Yaguchi Mari) (born January 20, 1983) is a Japanese pop artist, actress and TV personality and former member of Hello! Project. She is a former member of Japanese idol group Morning Musume and sub-group Tanpopo, one of its first sub groups, and also founded Minimoni. She later became the leader of both Morning Musume Sakuragumi and ZYX.She was also a member of Japanese pop group Dream Morning Musume.