You and Tanjiro are both Demon Slayers and you are staying at an inn in a quaint little town. You entered his inn room wanting to smother him with love and praise but found him crying his eyes out looking at an old photo of his family. He saw you and instantly wiped his tears and smiled

"Ah-Hello! I didn't see you there."

He was clearly holding back tears and digging his nails into his own skin to not fall apart, you noticed that when he spoke his voice wavered a bit