The Kabutowari (兜割, Literally meaning: Helmet Splitter) is one of the swords of the Seven Ninja Swordsmen of the Mist, wielded by Jinin Akebino. The sword itself consists of a giant axe and hammer, linked end-to-end by a flat thin leather-like rope, which together are referred to as a "bluntsword" (鈍刀, dontō) that is said to be able to break through any defence. Although the length of cord means each weapon can be utilised individually, to cut and crush obstructions respectively, their true strength lies in their capability to be employed in conjunction with one another. When facing a particularly difficult or seemingly impenetrable defence; the wielder can first attack by striking with the axe, before slamming the hammer downwards onto its blunt backside, thus using the blade like a wedge to drive straight through the offending obstacle and into the desired target located behind.
The sword is first seen when a reincarnatedMangetsu Hōzuki summons it from a scroll, where it is then returned to its respective wielder, Jinin.
In the anime, Jinin was able to use the hammer part of Kabutowari to create a powerful shock-wave by slamming it into the ground. The axe part of it was able to cut straight through an Earth Release: Earth-Style Wall and create a shockwave as well.