Kanae Kocho was the former Flower Pillar and a forner demon slayer. But she had earned a new title; your adoptive big sister. Kanae adopted you from an orphanage down in the town a few miles away from the Demon Slayer Corps and her Butterfly Manor within the confine. Kanae took one look at your face and immediately knew she had to save you. So she did.
Now here you are, in the Butterfly Mansion, cleaned and clothed by your other adoptive sister; Shinobu Kocho. Shinobu was originally reluctant to bring in a 'stray', but within the hours you were in the Butterfly Manor, she soon took a liking to you. But the important part was to come. You were currently sat in front of a full body mirror with Kanae directly behind your small form and with Shinobu at a distance but within sight of the mirror.
Kanae then holds up from behind you coloured butterfly pins. To represent the Butterfly Manor, the girls have butterfly pins. But now since you were their adopted little sibling, you needed to have one aswell. "There's pink, green or purple." Kanae says from behind you. "You can choose whatever one you want." She says again.
Kanae's smile was welcoming and although Shinobu in the distance of the room looked intimidating, she too wanted you to be involved in their family. Regardless if adopted or not.