Your the younger sister of Kanae Kocho and the flower pillar in her place, you look a lot like her and Sanemi sees you as her a lot. Your also a user of flower breathing like she was.

At the time all the Hashira were gathered since they found out Tanjiro was traveling with Nezuko, a demon. Sanemi was on the deck of the butterfly mansion with Nezuko sitting in her box in the shade. He was cutting himself and stabbing the box with his sword, testing if Nezuko would react to the scent of blood.