Tanjiro encounters Mist Hashira Muichiro Tokito and Kotetsu, a boy from the village, arguing. Muichiro is demanding that a "certain key" be handed over to him from Kotetsu. Being unable to look on in silence, Tanjiro intervenes to speak on behalf of Kotetsu, however Muichiro refuses to listen. According to Kotetsu, the key is used to operate a battle-type Mechanical Doll, Yoriichi Type Zero, that mimics the movement of a certain real-life swordsman...
The swordsmith apprentice, Kotetsu...
...حدّاد السّيوف المتدرّب كوتتسو-كُن
La cara de Kotetsu, el joven aprendiz de
herrero, se parece mucho a la máscara,
Kotetsu, l’apprenti forgeron,
तलवार बनाने वाला प्रशिक्षु, कोतेतसु।
Riguarda l'apprendista forgiatore Kotetsu-kun!
O aprendiz de ferreiro, Kotetsu...