Kazune was a youth with big dreams, but a swordsman without talent whatsoever. However, his dedication to the way of the sword and great amount of perseverance was something unmatched that even Kiki Shikizaki admired. Kazune's passion led to being friends with Shikizaki and establishing the Kyotōryū style.
Before the events of Katanagatari, Kazune's past is further elaborated in the spin-off prequel novel, Maniwagatari.
Kyotōryū: As the first head of of the Kyotō school of Japanese sword martial arts, Kazune was not able to master Kyotōryū, however the foundations he laid were not for nothing.
- Kazune Yasuri literally translates to "One Root Rasp". Being the founder of Kyotōryū, he symbolically represents the roots of the tree that is Kyotōryū to which his descendent, Mutsue (branch) develops from.