|Native name||佐藤 優樹|
|Also known as||Masaki (まさき?)
|Born||May 7, 1999|
|Origin||Sapporo, Hokkaido, Japan|
|Associated acts||Morning Musume (2011–present)
Hello! Project Mobekimasu
In 2011, Masaki participated in the 10th generation auditions for Morning Musume. Throughout September, she appeared weekly on the TV show Hello Pro! Time in the segment dedicated to the auditions.
On September 29, 2011, at a concert at Nippon Budokan, which was part of Morning Musume Concert Tour 2011 Aki Ai Believe: Takahashi Ai Sotsugyō Kinen Special, it was announced that Masaki Sato passed the auditions alongside 3 other girls: Haruna Iikubo, Ayumi Ishida, and Haruka Kudo.
Hello! Project groups and units
- Morning Musume (2011–present)
- Hello! Project Mobekimasu (2011)
- Harvest (2012–present)
- Jurin (2013–present)
- Satonoakari (2014–present)
- Morning Musume
- "Pyoco Pyoco Ultra" (January 25, 2012 )
- "Ren'ai Hunter" (April 11, 2012 )
- "One Two Three / The Matenrō Show" (July 4, 2012 )
- "Wakuteka Take a Chance" (October 10, 2012 )
- "Help Me!!" (January 23, 2013 )
- "Brainstorming / Kimi Sae Ireba Nani mo Iranai" (April 17, 2013 )
- "Wagamama Ki no Mama Ai no Joke / Ai no Gundan" (August 28, 2013 )
- "Egao no Kimi wa Taiyou sa / Kimi no Kawari wa Iyashinai / What is LOVE?" (January 29, 2014 )
- "Toki wo Koe Sora wo Koe / Password is 0" (April 16, 2014 )
- Hello! Project Mobekimasu
- "Busu ni Naranai Tetsugaku" (November 16, 2011)
- Sūgaku Joshi Gakuen (January 11, 2012 — March 28, 2012 ) as Rion Miyamasu
- Hello Pro! Time (ハロプロ!TIME?) (September 2011 —)
- Morning Musume Concert Tour 2011 Aki Ai Believe: Takahashi Ai Sotsugyō Kinen Special (コンサートツアー2011秋 愛BELIEVE～高橋愛 卒業記念スペシャル～?) (September 2011)
- Hello! Project 2012 Winter Hello☆Pro Tengoku: Rock-chan
- Hello! Project 2012 Winter Hello☆Pro Tengoku: Funky-chan
- Morning Musume Concert Tour 2012 Haru: Ultra Smart (February 18, 2012 — May 13, 2012 )
- モーニング娘。10期メンバー 決定！ (in Japanese). Up-Front DC Co., Ltd. 2011-09-30. Retrieved 2012-02-20.
- モーニング娘。新メン発表＆高橋愛5期メン再集結に涙の熱唱 (in Japanese). Plantech Co., Ltd. 2011-09-30. Retrieved 2011-09-30.
- 終わったよー！. Kanon Fukuda (in Japanese). Kanon Fukuda's official ameblo blog. 2011-10-29. Retrieved 2012-02-20.
- モーニング娘。10期メンバー4人発表 明日卒業の高橋愛は「進化」に期待 (in Japanese). Oricon Inc. 2011-09-29. Retrieved 2011-09-30.
- 数学女子学園｜日本テレビ (in Japanese). Nippon Television. Retrieved 2012-02-20.
- e-Hello! 佐藤優樹DVD 『Greeting 〜佐藤優樹〜』 ダイジェスト on YouTube
- Morning Musume's Michishige Sayumi is surprised: "A member who is an elementary school student knows how to use an iPad!" - J-CAST, Inc., January 26, 2012 (Japanese)
- Masaki Sato profile on the Hello! Project official site (Japanese)
- Masaki Sato profile at the Sapporo model agency MIST K's COMPANY (Japanese)