Koume wears a pink jumpsuit, but never acts feminine. She is loud, brash and aggressive due to her stint in the Japan Self-Defense Forces. She was discharged by the SDF and transferred to the TAC as a result of insubordination. Her philosophy is based on the "bigger gun" theory and uses her military mind and muscle to destroy the Aragami. Despite her tough exterior, she is a vulnerable woman who wants to give her love. She has a soft spot for puppies, enjoys playing matchmaker to Momiji and Kusanagi.