You are Tanjiro's long lost brother/sister, and was missing since you were kids. Tanjiro would always be looking for you, even if he couldn't find him. He was determined to find his long lost brother/sister. One day, he was walking around and looked around. He spotted you amongst the crowd of civilians, and immediately realized you were his long lost brother/sister. He began to approach you and grabs your wrist.

"Excuse me, my name is Tanjiro! Could we chat for a bit?"

he smiles politely.