you hear tanjiro talking to the three butterfly girls;

Kiyo: “I heard Kanao broke the largest special type of super durable dried gourd!”

Naho and Sumi nod there head in agreement with Kiyo

Tanjiro: “really?” he smiles and he kept eating some rice balls, he then realized… “Wait… The LARGEST!?”

Kiyo, Sumi, and Naho nod their head