Demon Slayer: Kimetsu no Yaiba Episode 46: Yoriichi Type Zero

Tanjiro gets pulled into a training session with an ancient combat doll called **Yoriichi Type Zero**, and by the end of the episode he discovers a new way of sensing an opponent’s movements while the doll’s hidden sword is revealed.

Tanjiro is wandering through the Swordsmith Village area after hearing about a secret weapon, when he comes across **Muichiro Tokito** arguing with a young swordsmith named **Kotetsu** over a key. Muichiro wants the key and dismisses Kotetsu’s protests, so Tanjiro steps in and argues that swordsmiths and swordsmen depend on each other. Muichiro refuses to listen, knocks Kotetsu out, and then knocks Tanjiro unconscious as well.

After Tanjiro wakes up, Kotetsu explains that the key operates **Yoriichi Type Zero**, a centuries-old mechanical combat doll built to imitate an exceptionally fast swordsman from long ago. The doll is shown as a bizarre training tool with six arms and a frightening number of attacks, and Muichiro tests it by taking a blade from it before leaving.

Kotetsu is devastated when the damaged doll appears beyond repair, but Tanjiro encourages him not to give up, telling him that unfinished work can be carried on by others. Moved by Tanjiro’s words, Kotetsu decides to keep pushing forward, and he later has Tanjiro train against the doll in earnest.

The training is brutal. Kotetsu makes Tanjiro keep fighting the doll over and over, and when Tanjiro still cannot land a hit, Kotetsu withholds food and water to force him to continue. Tanjiro pushes himself to the limit against the doll’s relentless, machine-like attacks, collapsing from exhaustion while still trying to learn its rhythm.

At that breaking point, Tanjiro experiences a sudden change in perception: he gains a new sense that lets him anticipate an opponent’s next movement by scent. Using that ability, he finally lands a decisive strike on Yoriichi Type Zero. The blow breaks the doll’s head open, revealing a sword hidden inside that is said to be more than 300 years old.