Item from Demon Slayer by Koyoharu Gotouge
A 300-year-old mechanical training doll with six arms built to replicate one swordsman's movements — because five arms weren't enough to simulate Yoriichi Tsugikuni's speed.
Yoriichi Type Zero was built during the Sengoku era by a master craftsman who wanted to create a training dummy that could replicate Yoriichi Tsugikuni's swordsmanship. He needed six arms because five weren't enough to simulate the speed and complexity of Yoriichi's Sun Breathing forms. Even with six arms, the craftsman admitted it was still an imperfect approximation. The doll served as a training partner for centuries, maintained by the Kotetsu family of swordsmiths. When Tanjiro trained against it until it broke, a hidden Nichirin blade from the Sengoku era fell from its chest cavity — a blade from the age of Sun Breathing practitioners. This blade became Tanjiro's final weapon, the sword he carried into the battle against Muzan. The doll's destruction revealed a gift three hundred years in the making.
A large mechanical puppet made of wood, metal, and articulated joints, standing upright in a training hall in the Swordsmith Village. Six arms extend from its frame, each holding a katana. The craftsmanship is extraordinary for any era — the joints move with fluid precision despite being centuries old. Its 'face' is a simple carved mask. The mechanism is wound with a large key. After centuries, it's battered and worn but still functional. A hidden Nichirin blade was stored inside its chest cavity.
Also known as: Type Zero, Yoriichi Doll, The Battle Doll, Mechanical Doll