Mutsue was the sixth head of the Kyotouryuu fighting style and the father of Nanami and Shichika.
During the previous rebellion, Mutsue was ordered by the Shogunate to assassinate the leader of the uprising: Takahito Hida, Togame's father. After defeating him and his army, the Shogunate exiles Mutsue to the uninhabited island of Fushou out of fear that the same skills that single-handedly defeated a rebel army might one day be used to defeat his own.
While on the island, Mutsue taught Kyotouryuu to his son and seventh head: Shichika Yasuri. Initially, Mutsue planned on making his daughter, Nanami, the 7th head but her skills and ability to mimic and master any technique after seeing it twice lead him to the belief that she was deviant and that he did not have the capacity to instruct someone as capable and talented as herself.
Mutsue 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. Mutsue, voiced by Toru Ohkawa, makes his first appearance in the anime series during Episode 1 "Plane, the Absolute".