The same age as Okita Sōji and another member named Tōdō Heisuke, the three shared the distinction of being one of the youngest in Kondou Isami's group and being among its most gifted swordsmen. As a member of the Shinsengumi, Saitō was said to be an introvert and a mysterious person; a common description of his personality says he "was not a man predisposed to small talk." Saito was an unusually tall man at 5' 11". He was also noted to be very dignified, especially in his later years. He always made sure that his obi was tied properly and when he walked he was careful not to drag his feet. At rest he always sat in the formal position, called seiza, and he would remain very alert so that he could react instantly to any situations that might occur.