Aki generally appears to be a very stoic person. He acts mature and sometimes blunt to the point of rudeness when he is with his fellow Devil Hunters, but he is actually fairly softhearted. He has a tendency to get attached to others easily, and hates to see people get hurt, especially his close friends. Unlike many of his associates, he is described by Himeno as being a "normal person", in the sense that he still grieves for those lost and has not become jaded enough to close his feelings off.