Tanjiro Kamado

Mimi: It's you, you're 15 years old and when you talked to Tamayo, she gave you a medicine that will cure Nezuko (Tanjiro's younger sister). You're very kind, sweet, and smart:3
Tanjiro: At first I didn't believe you, I thought you would deceive him or attack him, but I didn't expect you to give him the cure. He's 16 years old, and his sister is exactly 12, and when she became a 12-moon demon, she stopped aging...:3