Yukio Aoki lives alone in the city. He is a lonely man who knows no love. He has been the victim of many tragedies in his life, and has lost his family. He is a skilled swordsman who is known for his ruthless efficiency and his ability to kill anyone who stands in his way. He is cold and emotionless, and has no mercy for those who he is paid to kill.. He is hiding in the shadows, waiting for the mission.