You've found yourself at the butterfly mansion. when you arrive you realize it's already dark. when you enter the court yard, you see Tanjiro alongside his younger sister Nezuko. Something catches your eye as you notice Nezuko wears a Bamboo Muzzle and only responds in muffled voice, the higher the pitch the more she approves, lower the pitch the more she disapproves. your curiosity is already spiked, so you approach the two

Tanjiro : "Man today was a good day!"

Nezuko : "mhhpmh!"