Episode 46

Yoriichi Type Zero (緑壱零式) is the 46th episode of the Kimetsu no Yaiba TV anime series, and the 2nd episode of its third season.

Summary
Watching Muichiro Tokito arguing with a young swordsmith, Tanjiro steps in to defend him but discovers that the talented and indifferent Mist Hashira both is and isn't who he appears to be. Helping the young smith, he discovers the man from his dream with them is actually a special battle doll for training, inspiring Tanjiro to know who he is and improve his skills against a unique opponent.

Plot
The young swordsmith continues to refuse Muichiro’s request for a key, as well as claiming he would not show how to use “it”. As Tanjiro watches the argument behind the trees, believing he should mediate, the annoyed Mist Hashira chops at the boy’s neck, rendering him unconscious. Tanjiro rushes in and confronts Muichiro, demanding he let go; he attempts to pull his hand away from the smith but cannot move the Hashira’s arm despite him being thinner and smaller.

The Hashira instead demands that he let go and elbows the Demon Slayer’s stomach, sending him to the ground in pain. He insults Tanjiro for being weak and wonders how he entered the Demon Slayer Corps, before he senses a demon inside the box he is carrying. Tanjiro swats his hand away and demands he does not touch it. He pulls the young smith from Muichiro’s hold, somewhat surprising him, but the upset swordsmith refuses Tanjiro’s help and declares again he would not give the key, believing the item he is worried about will break.

Muichiro insults him for believing he could hold out on such circumstances and reasons that he could made another one. He asks how many people might have died in the time he is refusing to give up something trivial and remarks that a Hashira’s time is more valuable than his; since he cannot fight, all a swordsmith is good for is making weapons. Muichiro asks for the key once more, only for Tanjiro to step in to defend the smith.

The frustrated Demon Slayer claims that he cannot stand the Hashira's demeanor, and while he concurs with his statements, he adds that a swordsmith’s job is still vital, as a swordsman and a swordsmith cannot exist without each other. Muichiro suddenly cuts him off and states that he has no time to listen to a “boring speech”, before chopping at Tanjiro’s neck to knock him unconscious.

Some time later, Tanjiro eventually wakes up, asking if Haganezuka had been around, but the swordsmith states that he is not. He then asks for Muichiro's whereabouts and the smith states that he gave him the key to fend him away. Though he is dismayed he interjected in a hopeless argument, the boy thanks Tanjiro for defending him. He then asks about the man who was with them but is told it was a mechanical doll, which needed the key. The young smith states that the combat doll is capable of 108 movements and can overpower a person, before the two then hear a loud clash, with the smith realizing that Muichiro has activated it. Tanjiro and the swordsmith watch as Muichiro engages the battle doll in a rapid skirmish. The smith states that it was built by his ancestors and is known as Yoriichi Type Zero. Tanjiro asks why it has six arms and the boy responds that according to his father, the doll is based on a real person but six arms was needed to replicate how fast the person's movement was. Looking at the doll's face, Tanjiro recognizes it but cannot pinpoint its familiarity, asking the smith who the person was, but even he does not know as the person was from the Sengoku period. Amazed at 300 year old technology still not replicated now, the smith then solemnly notes that if it was to be broken, it cannot be fix by anyone, with Tanjiro realizing why the doll means so much to him.

As he watches Muichiro fight, he is amazed at someone so young being so talented. A shrill voice comments that Muichiro's prodigious skill is due to being a descendant of the wielder of Sun Breathing; it is Muichiro's Kasugai Crow. When Tanjiro notes that the Hashira doesn't use Sun Breathing, the crow bites him for insulting her owner. The Demon Slayer then notes that he saw the man in a dream but the crow lambasts his claims that he knows someone from the Sengoku period.

The swordsmith then realizes that he perhaps saw an inherited memory, and possibly one of his ancestor's. Happy that his claims are not out of proportions, Tanjiro asks for the boy's name, who replies he is Kotetsu. They then hear a loud crash as Muichiro lands a blow on the doll, causing extensive damage. Seeing this, Kotetsu runs away in anguish. Using his sense of smell, Tanjiro eventually locates Kotetsu up in a tree and offers his help, while remarking that he cannot give up on the doll. He states that he must try for his future self but Kotetsu refuses to continue, believing all his generation's accomplishments will end with him. Suddenly, he notices Tanjiro hanging by a branch beside him and is flicked in the chin, shocked and amazed that the Demon Slayer climbed up quickly and silently. Tanjiro claims that even when he cannot do something now, someone will help him, and even if it is something beyond him now, his descendants will eventually do it. He proclaims his desire to defeat Muzan Kibutsuji and save Nezuko but even he could die before fulfilling it, yet he remains hopeful someone will do it for him. Clutching Kotetsu's hand, the Demon Slayer declares that they do their best together, bringing the young swordsmith to tears and inspiring him to continue. As they walk back to the doll, they notices Muichiro now on his way, having finished what he believed was a successful training session. The Mist Hashira then mentions that his own sword was snapped in doing so and he will now be using one from the doll, holding a broken off arm with a blade. Kotetsu then hurries to the doll while Muichiro orders Tanjiro to dispose of his old sword, tossing it at his head. Seeing his dismissive actions, Tanjiro notes that he does not bear any malice and seems to not be doing it on purposes, though remarks that the same cannot be said of his crow.

As rain falls, Kotetsu dejectedly looks at the damaged doll but Tanjiro wants to test if it is still functional. Setting up upright and turning the key, they are amazed to see that Yoriichi Type Zero still works. Still angered by Muichiro, Kotetsu then desires for Tanjiro to train with the doll in the hope of surpassing the Mist Hashira. Even while fighting the doll now armed with wooden clubs, Tanjiro is overwhelmed by its speed and unable to land a hit. Moreover, in spite of his earlier inability to defend himself, seeing a way to beat Muichiro at his own game reveals that Kotetsu is both hot-headed, barbed tongued, and keenly analytical, repeatedly insulting the Hashira in front of the Demon Slayer and teaching him on his errors in engaging the doll. Wanting him to feel the urgency of beating it, Kotetsu forces Tanjiro to train without eating or drinking as punishment. Regardless, Tanjiro is still unable to land a blow and the lack of food is weakening him further, making the task even more difficult.

A slight rain offers Tanjiro something of a drink but eventually, he suddenly faints mid-battle with Yoriichi Type Zero, now armed by Kotetsu with real swords. Seemingly seeing himself in the Sanzu River, Tanjiro walks the bridge to the afterlife but accidentally falls into the river. While dizzy from the hunger and surrounded by dark water, he feels himself being warmly massaged and sees a shiny stone at the bed, even able to smell it. Upon touching, he finds himself awake again and mid-attack with the battle doll. He detects a new scent different to the Opening Thread and looks at specifically moving arms and legs of the doll. Now knowing how to attack, Tanjiro dodges a swing to his head and gets down low, but he fails to make significant contact and slumps to the ground. Seeing his closest successful strike yet, Kotetsu offers some food, much to the exhausted and weary Tanjiro's gratefulness.

Having eaten and regained his stamina, Tanjiro fares better against the bladed Yoriichi Type Zero and is able to see its movements before they happen. Backing away to plan a strike, he sprints at the doll and leaps up, going over it as he descends and bringing his blade down to slash it. However, he pauses mid-attack, unwilling to destroy something too valuable to Kotetsu. Unexpectedly, the swordsmith calls for him to strike it, realizing he can still fix it should it break and allowing Tanjiro to finish his goal. As the doll nearly hits him, cutting through his hair, Tanjiro twists his body and makes contact, breaking the blade he was using and falling to the ground. Kotetsu runs to him and the Demon Slayer apologizes for the broken sword, but the smith does not mind. They then hear as the doll's body breaks open from where it was hit, the head crumbling away to reveal a sword hidden inside. Tanjiro and Kotetsu are in disbelief to see a sword over 300 years old before them.

Characters in Order of Appearance

 * Muichiro Tokito
 * Kotetsu
 * Tanjiro Kamado
 * Yoriichi Type Zero
 * Hotaru Haganezuka
 * Yoriichi (Flashback)

Anime Notes

 * In the manga, as Muichiro attempt to reach towards Nezuko's box, Tanjiro angrily smacks away his hand with considerable force, even causing Muichiro's hand to ache. In the anime, Tanjiro weakly swats away his hand.
 * In the manga, Tanjiro's Kasugai Crow and Muichiro's are shown squabbling with each other, which was not depicted in the anime.
 * The sword Muichiro takes as his own is sheathed in the manga but not in the anime.
 * In the manga, Kotetsu shows that Yoriichi Type Zero can be set to utilize the weaknesses of an opponent by making adjustments to the head's configuration and by rotating the fingers a certain amount of times, which means that Muichiro was unable to optimize his training. This was not shown in the anime.