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. Unlike many of his associates, he was described by Himeno as being a "normal person", in the sense that he still grieved for those lost and had not become jaded enough to close his feelings.