Saya Minatsuki

A Sweeper who found and helped Train when he was injured. She introduced him to a new world, so to speak, and helped him become the man he is now. Their relationship was deep, and was not romantic (According to Train), but may have been if given more time. As the manga progresses, we learn more about Saya and her relationship with Train, as well as about Train's childhood and traumatic past. Her weapon of choice in both the manga and anime is a Beretta 93R, and her special technique was ricocheting bullets at different angles and velocities.