One of the twelve heads of the Maniwa Corps and the wielder of Zettou Kanna
Koumori is a character in the Katanagatari series of light novels written by Nishio Ishin, a popular Japanese writer, with illustrations by Take. He also appears in the anime series of the same name which was created by White Fox and directed by Keitaro Motonaga. Koumori, voiced by Chihiro Suzuki, makes his first appearance in the anime series during Episode 1 "Plane, the Absolute".
After following Togame to Fushou Island and hearing her conversation with Shichika and Nanami, Koumori attacks the house that the three are in and Shichika rushes off and to engage him in combat. When the battle comes to a stalemate, Koumori retreats into the woods, taking Togame with him. Using his ability to change his shape, his transforms into Togame and heads off to find Shichika in order to kill him. However, his plan backfires when Shichika, who is terrible at recognizing faces, blindly attacks Koumori-Togame. Injured and shocked at Shichika's stupidity, Koumori tries to turn Shichika against Togame by telling him her true past: Togame is the daughter of the man Shichika's father was ordered to kill (and killed in front of her no less) and that her mission is solely to collect the weapons on her own behest so that her ranking in the military and government will increase.
Koumori's plotting has an opposite effect as Shichika feels sorry for her after hearing the tale and decides to assist her. Koumori attacks Shichika by transforming into him to gain his superior strength but makes a critical mistake when he tries to wield Zettou Kanna. It's not a case that Kyotouryuu users don't wield swords, it's that they can't wield them, which causes Koumori to drop his weapon in the middle of an attack and Shichika counters him with a brutal series of attacks, ending both the battle and his life.