Aki is a young man with black hair and blue eyes. He wears his hair as topknot, alongside wearing his Devil Hunter uniform with suit and tie. Aki is a no-nonsense Devil Hunter who dislikes members not being serious about their duties, putting it to himself to discipline them as well as disliking members who are only in it for the money. Aki is also extremely vengeful towards Devils, ensuring they all die painfully, as well as deeply mistrustful of other Devils as well as Hybrids and fiends.