Saito is the principal sniper of Public Security Section 9. He possesses significantly less cybernetic augmentation than most teammates. His key prosthetics are a cybernetic left arm and the "Hawkeye" – a satellite-linked prosthetic left eye granting extraordinary long-range accuracy. This ocular implant interfaces with orbital systems to compute environmental factors like wind and trajectory, though it remains hackable.

Prior to Section 9, Saito was a mercenary sniper for the private military group Red Bianco during World War IV. He engaged United Nations peacekeepers in Monterrey, Mexico, eliminating several soldiers under Motoko Kusanagi's command. Their clash culminated in a rooftop duel: Saito's shot grazed Kusanagi's cheek, but her return fire shattered his rifle scope, driving glass into his left eye. She then pinned his left arm with a combat knife, costing him both eye and arm. Kusanagi subsequently recruited him, declaring he now belonged to her. Saito later recounted this event during a poker game with Section 9 colleagues; contextual evidence implies the narrative's validity.

His tactical value extends beyond marksmanship. He anticipates enemy sniper behavior, aiding Section 9 in locating hostile positions on numerous operations – a skill born from extensive combat experience. He exhibits impatience with routine assignments and openly dislikes mundane tasks.

In *Solid State Society*, set two years after *2nd Gig*, Saito undertakes a demanding African mission. Opposing sniper gunfire damaged his left arm during the operation, though he eliminated his target. A subsequent conversation with Batou implied potential upgrades to his cardio-pulmonary system, indicating rising cyberization possibly causing his fatigue. This development contrasts his earlier status as one of Section 9's least augmented members.