Aki generally appeared to be a very stoic person. He acted mature and sometimes blunt to the point of rudeness when he was with his fellow Devil Hunters, but he was actually fairly softhearted. He had a tendency to get attached to others easily, and hated to see people get hurt, especially his close friends. He is energized by time spent alone, he focuses on facts and details rather than ideas and concepts, who makes decisions based on logic and reason rather than emotion.