Sato Masaki (佐藤優樹) is a soloist under UP-FRONT GROUP's M-line club. She is a former 10th generation member of Morning Musume (モーニング娘。), as well a former member of the SATOYAMA movement units Harvest (ハーベスト), Jurin (ジュリン) and Sato no Akari (さとのあかり). Sato Masaki was selected from Morning Musume's 10th Generation audition to join the group on September 29, 2011, along with Iikubo Haruna, Ishida Ayumi, and former Hello! Pro Egg Kudo Haruka.