The Shigure Kintoki is a bamboo sword that transforms into a metal sword when Shigure Soen Ryu is used.
It is a typical brown bamboo sword that transforms into a steel sword with bandages on its hilt. A swallow is engraved near the scabbard mouth.
The Shigure Kintoki has been passed down through Yamamoto's family for generations, used only by those who mastered Shigure Soen Ryu. The Shigure Kintoki first appears as a plain-looking bamboo sword, but it is revealed that only if the user uses the Shigure Soen Ryu technique will it shed its bamboo cover. The katana will turn back into a bamboo sword once it is not used for a Shigure Soen Ryu technique.