He was born in Machida, Tokyo, and raised in Aobadai, Yokohama after living in Saginuma, Kawasaki.
[1] He graduated from Yokohama Municipal Nara Junior High School, Nihon University High School,[1] and Nihon University Faculty of Commerce Department of Commerce.
[2] After leaving Rakuten, he entered Yoshimoto General Performing Arts College (NSC).
When Saito was a high school student, he lost his mother at the age of 38 because of breast cancer,[1] and since then he grew up in his father's family.
[5][1][4] His IQ test on the TV Asahi series broadcast on 1 January 2016 Geinōjin Kakuzuke Check 2016 Dai Yosen-kai showed a high value of 132.