- Name: Yagi Shiori (八木栞)
- Birthdate: September 19, 2003
- Birthplace: Aichi, Japan
- Blood Type: O
- Specialties: Vocal music, ballet, back bridge with no hands
- Hobbies: Singing, watching musicals (especially Shiki Theater Company productions)
- Looks Up To: Kanazawa Tomoko, Kishimoto Yumeno, Nishida Shiori
- Hello! Project groups:
- Tsubaki Factory (2021–)
Yagi Shiori was announced to be a winner of the Hello! Project "Juice=Juice" "Tsubaki Factory" Goudou Shin Member Audition in a surprise reveal during episode #383 of Hello! Project Station. She would join Tsubaki Factory alongside fellow audition winners Kasai Yuumi and Fukuda Marine, as well as Hello Pro Kenshuusei member Yofu Runo. Their activities with the group began at the Hello! Project 2021 Summer Sapphire & Ruby concerts starting July 17.
- TV Programs
-  Ikuze! Tsubaki Factory (行くぜ!つばきファクトリー)
- [2020–] Hello! Station (ハロ！ステ)
- Has learned ballet and jazz dance.
- Participated in swimming and chorus.
- Admires Kishimoto Yumeno for her singing and personality gap.
- Her favorite Hello Pro Kenshuusei trainee was Yofu Runo. She's happy to debut with her in Tsubaki Factory.
- In her introduction, stated she wanted to improve her skills to match the rest of the group, and that she wants to become a member able to lead the way for the rest of Hello! project.
- Her favorite type of music is songs from musicals.
- Her favorite sport is swimming.
- Her motto is "Kokorozashi aru mono wa kototsu ni naru" (志ある者は事竟に成る; One can achieve anything with ambition).
- Her favorite food is ice cream.
- Her favorite Shiki Theater Company production is "Yume Kara Sameta Yume" (夢から醒めた夢; A Dream Within a Dream).
- She has a pet Maltipoo.
- She found out about & applied to the Hello! Project audition while her school was closed because of COVID-19.
- Frequently listened to CHICA#TETSU's "Takanawa Gateway Eki ga Dekiru Koro ni wa" before auditioning.