Note: This has a follow-up. Check out "Pale Shores."
I'd also like to point out that I mentioned Yoruichi because I feel she had an important role in his life. So please, I don't really care if you don't like Byakuya/Yoruichi. Review my story, not the pairing (suggested or otherwise) in it. Thank you.
Each day, Byakuya sits in his study and listens.
He listens to the dull, everlasting silence. Rukia's bedroom is beside the study, and each day, he sits and listens to her stillness. Sometimes, she ventures outside to train; her breath is light as the blade cutting the air. He can hear her footsteps on the floorboards when she paces her room. If he listens hard enough, Byakuya can hear her clothing rustle as she moves.
Each day, Byakuya opens the same book and reads the same pages; there is no use learning what one already knows. He can recite each of these chapters, volumes, and tomes by heart. There is not a word in this room he has not read.
But he needs something to fill the space of silence between them, between their attempted brother-sister relationship. The bridge of their siblinghood is in slow repair; each day they tend to it, board by board, nail by nail. It has been a slow process, neither quite knowing how a brother and sister should behave, when all this time they have only been a man named Byakuya and a girl named Rukia.
Byakuya likes to think of himself a capable elder brother. He looks after his little sister and provides her with whatever desire she may have, however small. Byakuya would give her the cosmos on a necklace, had he the power to do so. He has come to love her as only a brother can.
The one thing he cannot provide is solace.
These past three months since the Winter War have been hard. The Seireitei has been silent for the sake of those lost, their names yet too fresh with death to speak. People pretend to go about life as it were before, although that life has been lost in the debris of war. Byakuya himself has long since given up searching through its shade.
Rukia has not.
It's in the sallow shade of her cheeks and the darkness in her eyes. He can feel it in her spirit when it touches his own. It hides on her shoulder, crouched like a specter in the night. The hand of loss has been on Byakuya's shoulder for so long, it has become a familiar presence. An unwanted friend he cannot shake.
If the Kuchiki lord could, he would take the weight of her loss to bear, but knows he cannot. The only thing he can do is meet her gaze and say, silently, I know.
He knows it all too well.
(Because only fifty years ago it was Hisana, and before her Yoruichi, over and over and over again).
Byakuya knows it is Ichigo Kurosaki she longs for the most. It's likely his face which fills her dreams at night, his name which rings, tauntingly, on the edge of her lips when she wakes. Each evening when she thinks he cannot hear, Rukia cries alone in her room, and it pains him, because she is his little sister, his little sister.
He can only listen to her silence, watch her walls go up each day, and read empty books to fill the spaces between them.