Aki is a very stoic and serious person. He is responsible, distant, and strict, and often seen with a stern expression. He acts indifferent and sometimes blunt to the point of rudeness, but he is secretly fairly sensitive. Aki is protective of those around him and hates to see people get hurt, especially his close friends. Despite acting cold and detached with others, Aki is not as closed off as he seems. He is ruthless in seeking revenge for his family, who were killed by the Gun Devil.