Mirai stared at her sister's sleeping face. Rei had fallen ill with a fever, and Mirai had leapt at the chance to take care of her, much as Rei had done for her as children. She could almost laugh; how did a shut-in like Rei get sick in the first place? But she didn't mind, as it was only the two of them, just as it should have been.
Well, almost. Thelema slept in her usual spot next to Rei's bed. Something dark began to stir within Mirai, but then she chided herself for being jealous of a dog. Besides, Thelema was an old dog, the same age as Rei, so eventually she would pass away and Mirai would be there to console Rei, and Mirai would protect Rei from any more grief.
"Big Sis…" Mirai murmured, laying her hand over Rei's warm forehead. "I'm here with you now, and I won't ever leave you again, I promise."
Rei stirred, and her face was pale and flushed. Her lips moved weakly, and all that she could say was a name that was like a knife to Mirai's heart: "Yuri…"
Mirai scowled. Minano Yuri, that deceitful girl who had tried to take Rei away while Mirai was gone. But she'd spared Yuri's soul, allowing Yuri to wander Purgatory while she transcended time and space to achieve Revival and reclaim the time that had been taken from her. Alcea, a special kind of Idea, some of the older Revenants had called it. Mirai didn't quite understand, but she didn't care. All that mattered was that she had returned to her beloved sister.
A dark chuckle slipped from her lips; after all, her precious big sister was so very useless without her, so of course she had to achieve Revival, no matter the cost, to take care of Rei. No one else could love her like Mirai did.
Mirai took Rei's hand between hers, and Rei seemed to calm. "You always held my hands whenever I had nightmares, Big Sis," she said softly. "And now I can do the same for you! My poor sister, all those nightmares you must've suffered alone while I was gone…"
Often Mirai still had nightmares too, of being taken away from Rei, of their parents trying to return her like some defective toy because she wasn't Rei's stillborn twin sister. She'd once overheard their parents talking about Rei's lost twin, and sometimes she found herself hating this "Kuon," but she hated their parents even more for constantly comparing her to a girl who had never existed. She had loved them once, maybe not as much as she loved Rei, but she'd been grateful to them for giving her such a wonderful big sister.
Her fingers tensed, and she bit her lip, nearly hard enough to draw blood. So what if she wasn't Kuon? Rei loved her, and she loved Rei. Why hadn't that been enough?
But it didn't matter anymore. Their parents were dead, their souls consumed in the name of Revival, and finally Mirai had Rei all to herself. That was more than she ever could've asked for.
"Mirai…" Rei moaned, and her eyelids fluttered, as if she was still trying to dream.
"Oh, Big Sis, you look so pathetic right now, but also kind of cute and vulnerable," Mirai giggled. She caressed Rei's cheek, tracing Rei's lips with her thumb. "That's why I love you so much."
She and Rei weren't related by blood, so they couldn't be real sisters, those two who had pretended to be Mirai's parents had constantly told her. Kuon, a girl who had never been born, was Rei's true sister, and Mirai had failed to live up to that ideal. If all that was true, if Mirai really was a defective toy that could be returned on a whim, then there was nothing wrong or immoral about how she felt toward Rei.
Kneeling at Rei's bedside, she let her fingers lace with Rei's and leaned forward to press her lips against Rei's. She'd probably catch Rei's fever, kissing her ill sister like this, but if it meant Rei fussing over her, she wouldn't mind. Society didn't accept her as Rei's sister because they weren't related by blood, but neither would society accept her love for Rei. They were both girls, they were just pretending to be a family - Mirai didn't care about any of that. Maybe not even Rei would accept this love, but she at least accepted Mirai as her sister, and Mirai loved her big sister most of all.
As she broke the kiss, Mirai laid her head on the bed sheets, holding Rei's hand in hers. "That'll be my little secret," she said, gently poking Rei's soft cheek with her free hand. "You don't mind, right, Big Sis…?"
In death, she had been known as the Revenant Princess, allowing nothing to stand between her and Revival, all for the sake of the big sister she loved so much. Nothing else mattered, as long as Rei's heart belonged only to her.