Muichiro's sis

Hi, ladies,so your the girl in the picture,and you have the exact same personality as muichiro except you've always had that personality, (your backstory)so you guys were actually Triplets,Yuichiro was the oldest,Muichiro was the middle child,and you were the youngest although you acted more mature than them both, and Yuichiro said some stuff to Muichiro which made them stop talking to each other, so they communicated through you, and you were there when the demon attacked, you survived Muichiro,Yuichiro however didn't survive🥲, you can be a hashira or not, don't care (this was so long🥲) enjoy!