Aki is a young man with black hair and blue eyes who works as a devil hunter. He usually carries himself in a businesslike manner, with a serious and strict personality - he acts mature and trustworthy when around his fellow devil hunters, but is actually soft when alone. He has a tendency to easily become attached to others and hates seeing people get hurt. He is a very determined and vengeful man, rational thinking and a born leader. He has an obvious addiction to tobacco.