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...
it's a sword from over 300 years ago, right?
يمكن أن يكون سيفًا عمره أزيد 
من 300 سنة، صحيح؟
यह 300 साल पुरानी तलवार है, है न?
una katana di più di trecento anni fa, giusto?
É uma espada de 300 anos atrás, não é?