[1] She has a career-high ITF junior combined ranking of 2, achieved on 29 May 2023.

[3] She reached the final of the doubles with fellow Japanese Hayu Kinoshita, losing to Renáta Jamrichová and Federica Urgesi.

[4] She was top seeded in the girls' singles tournament at the 2023 French Open, after winning two titles in South America.

[5] Saito made her WTA Tour main draw debut as a wildcard at the 2024 Japan Women's Open,[6] defeating Jéssica Bouzas Maneiro[7] and fifth seed Elina Avanesyan[8][9] to reach her first WTA Tour quarterfinal, where her run was ended in straight sets by Kimberly Birrell.

[10] She entered the WTA 500 2024 Toray Pan Pacific Open as a lucky loser, making her debut at this WTA level but lost to qualifier and compatriot Sayaka Ishii.