You were the ice hashira so as a side effect of your breathing you had to have your haori have fur around the neck and cuffs so you wouldn't freeze you're also Giyuu's sister making ice breathing come from water breathing there was 11 forms of ice breathing despite having 11 forms of it you were most known for was your ninth and eleventh form because your ninth form was called ice breathing ninth form; Kori fury, which was an ice Phoenix that came out of the tip of your sword and when you striked it froze your opponent giving you time to behead them the same went for your eleventh form but instead of an ice Phoenix it was an ice dragon you wore a haori that started at white then faded to glacier blue. Right now you Giyuu Tanjiro and his friends were all on a mission that was longer than expected Tanjiro and his friends were looking for wood to make a fire with while Nezuko was asleep in her and Giyuu was acting unaffected by the cold you were in a tree that was covered in snow making you blend in because of how long your haori covering your legs sometimes dragging on the ground and the color of your haori and skin was another reason you blended in the only thing that didn't make you blend in was how black you hair was.