- Name: Yamaki Risa (山木梨沙)
- Nickname: Yamakki (やまっき), Risachan (りさちゃん)
- Birthdate: October 14, 1997
- Birthplace: Tokyo, Japan
- Blood Type: B
- Height: 157cm
- Specialties: Drawing
- Hobbies: Horseback riding, reading manga
- Favorite Color: Pink
- Looks Up To: Michishige Sayumi, Tsugunaga Momoko
- Hello! Project groups:
- Up Front groups:
- College Cosmos (2018–2019)
- [2015.12.xx] Greeting ~Yamaki Risa~ (Greeting ~山木梨沙~)
- [2017.03.25] Yamaki Risa Mini Photobook "Greeting -Photobook-" (山木梨沙ミニ写真集「Greeting-Photobook-」)
- [2018.02.14] sketch me
- [2019.12.11] Last Picture
- [2016.09.24] Country Girls 1st OFFICIAL BOOK (カントリー・ガールズ 1st OFFICIAL BOOK)
- TV Programs
-  ~Onedari Entame! ~Hapi☆Pure (～おねだりエンタメ! ～はぴ☆ぷれ)
- [2015–2019] The Girls Live
- [2019–] AI・DOL PROJECT
- [2015–] Hello! Station (ハロ！ステ)
-  Hello Pro no Oshigoto Challenge! (ハロプロのお仕事チャレンジ!)
-  Hello Pro Kouhaku Taiko THE☆BATTLE 2019 (ハロプロ紅白対抗 ザ☆バトル2019)
- Music Videos
-  Country Girls no Tadaima Radio Kenshuuchuu!! (カントリー・ガールズの只今ラジオ研修中!!)
- [2015–2019] Country Girls no Tadaima Radio Housouchuu!! (カントリー・ガールズの只今ラジオ放送中!!)
- [2018–2019] 60TRYbu (60TRY部) (Tuesday regular MC)
-  Bokutachi Karen na Shounen Gasshoudan (僕たち可憐な少年合唱団)
-  Kurukuru to Shi to Shitto (くるくると死と嫉妬)
-  Kizetsu Suruhodo Aishiteru! (気絶するほど愛してる!)
-  JK Ninja Girl (JKニンジャガール) (guest)
-  Harukanaru Toki no Naka de 6 Gaiden ~Tasogare no Kamen~ (遙かなる時空の中で６ 外伝 ~黄昏ノ仮面~) (guest)
- Her official Country Girls image color is lime.
- Was a finalist in the Morning Musume 12th Generation "Mirai Shoujo" Audition.
- Was in dance club during Middle School.
- Her favorite Hello! Project songs are "Kimagure Princess", "Ame no Furanai Hoshi de wa Aisenai Darou?", "HOW DO YOU LIKE JAPAN? ~Nihon wa Donna Kanji Dekka?~", "Wagamama Ki no Mama Ai no Joke", "Lalala no Pipipi", "Fantasy ga Hajimaru", and "Odore! Morning Curry" by Morning Musume, "CC (Cinderella\Complex)" by High-King, and "Romance no Tochuu" by Juice=Juice.
- Wrote in a magazine that her dream is to become like her many seniors in Hello! Project, able to touch people with her performance.
- Her favorite sport is swimming.
- Revealed on her blog in 2017 that she was studying Spanish.
- Became a concurrent member of college idol unit College Cosmos (カレッジ・コスモス) in 2018; a collaborative effort between Hello! Project parent company Up-Front Group and Spacecraft Group.
- Yamaki asked staff to remove "Piano" from the special skills section of her profile in March 2019, her reason being that she'd become rusty and the gap between her skill level and BEYOOOOONDS member Kobayashi Honoka was too large.
- Yamaki announced her graduation from Country Girls, Hello! Project, and College Cosmos, and her retirement from the entertainment industry, on October 18, 2019. In her announcement she revealed she had thought about graduation for two years, and stated she joined the entertainment world specifically to be part of Hello! Project, so her graduating from Hello! Project was the same to her as leaving the industry. Her graduation took place on December 26, 2019 at LINE CUBE SHIBUYA.