Kubikiribōchō

This giant blade was used by Zabuza during his membership as one of the Seven Swordsmen of the Mist. After defecting from Kirigakure, he continued to use it up until his death. It was left beside his grave, near the Great Naruto Bridge, until Suigetsu took it for himself three years later. In the manga, Suigetsu simply takes the blade from Zabuza's grave. In the anime, after Zabuza's demise, the blade was stolen by Tenzen Daikoku, a crime boss who lost many men to the blade, as a trophy, and was used by one of his bodyguards until Suigetsu took it forcefully.

The sword is shaped like a giant butcher knife. It has a circle cut out of the top and the semicircle near the handle, which, as demonstrated by Suigetsu, seem to fit the sword's purpose of decapitation aptly, and gives something to wrap a back strap around. Its handle also appears to be detachable, as Suigetsu is shown screwing it off when not in combat and reattaching it for combat. While the handle is removed, it is relatively short. When reattached, however, it seems to extend by about four times its length. Suigetsu, despite being well-trained, notes the heaviness of the blade can tire him out easily. The Decapitating Carving Knife was damaged by Killer Bee and left at his training zone after Taka fought him. Suigetsu was upset that, despite saving him while he was unconscious, they had left the sword behind. The blade was later retrieved as Taka prepared to head towards Konoha.

When Suigetsu attempted to block a strike from the Fourth Raikage with the blade, it snapped in half, as the nick that the blade suffered from the fight with Killer Bee weakened it. Despite this, Suigetsu still used it to fight against Darui's sword, and kept it even after the battle. However, while disguising himself as a samurai, the broken sword is no longer seen in his possession.

Trivia

 * This is the only one of the seven blades of the Swordsmen of the Mist shown so far to not have any special abilities.
 * Even after it was broken this sword still looks like a butchers blade, the sword now looks more like a Cleaver than a knife.