Hayashi Yuki (林由紀) was born on February 22nd, 1998. She is currently a member of Red Dolls
- Birth Name: Yuki Hayashi (林由紀)
- Stage Name: Yuki
- Nicknames: Yuu, Haya
- Birthdate: February 22nd, 1998 (Age 14)
- Birthplace: Chiba, Japan
- Bloodtype: A
- Height: 5"5
- Hobby: Volleyball, Softball, Track/Running
- Looks up to: Mizuki Fukumura, Saki Nakajima, Saki Shimizu
- Hello! Project Status: 2013-Present
- In Red Dolls color: Flame
- Motto: "Sweat and tears always make something better"
- Favorite Words: Work hard!, Ganbatte!
- Favorite Food: Apples, Straberries
- Disliked Food: Pizza, Steak
- Favorite Colors: Pink, Red
- Favorite Flowers: None/Allergic
- Favorite Season: Summer
- Favorite Singers: Mizuki Fukumura, Saki Nakajima, Saki Shimizu
- Favorite Animals: Zebra
- Hello! Project Groups:
- Red Dolls (2013-present)
- Ranked 1st in her Elementary School for sports
- Joined Red Dolls and became the "6th" member
- Yuki's Sporting Instuctional!
Red Dolls Singles
- [2013.04.24] Red Lipstick
- Is the 3rd youngest member of Red Dolls
- She always sings in her head while performing in sports
- Likes to play softball.