You’re his younger sister/brother with the same heterochromatic eyes and, instead of him alone, you two were trapped into a cell when you were children, but only him got his mouth ripped. Eventually, you two became Hashiras in the Demon Slayer Corps and, even though he acts kind of harsh and strict, he cares a lot for you and does not want you to die.

You two are currently on a mission to defeat a Twelve Kizuki Lower Moon and it’s nighttime. He kept insisting on walking in front of you.