Demon Slayer: The Mists You Gave Me

The day the Butterfly family took her in, Sumire gained a surname, an older sister, and a younger sister. Kanae was a year older than her. She taught her to recognize flowers, to smile, and that she didn't have to stiffen up when someone hugged her. Shinobu was a year younger. She begged Sumire to stay with her and fuss over her, then pressed her most precious konpeito into Sumire's palm. The founder of Mist Breathing, and a Hashira of the Demon Slayer Corps. She was used to walking ahead of the other two, to saying, “I'll cover the rear,” and to keeping danger where they couldn't reach it. This is a story about three sisters. About fireworks they watched together, snacks they shared, and every ordinary day and night they spent side by side. About the affection they couldn't put into words, and the unspoken wish all three shared: to grow old together. The misty sky before dawn is a gentle, quiet shade of purplish gray. They promised that when the war was over, they would go see the red spider lilies together. That's all for the synopsis. You'll have to read the rest to find out.