In March 2019, he and the other members of Hypnosis Mic received a singing award in the 13th Seiyuu Awards.
At the 9th Seiyu Awards in 2015, Saito won the "Best Male Newcomer" award for his role as Twelve. He shared the award with Ryota Osaka and Natsuki Hanae.
He had his first solo live concert at Maihama Amphitheater on February 24, 2019.
He's the eldest of three siblings, with two younger sisters.
In 2009, Saito won the "Judges' Special Prize" in the recitation competition at the 33rd National High School Comprehensive Cultural Festival. Veteran voice actor Nobuyo Oyama was one of the judges present at that time.