When a son was born to the Kuchiki household, not all of Soul Society rejoiced. Not many people cared. Certainly there were those who were interested, but the doings of the nobles were not the concern of most of the rest of Soul Society.
It was, however, of great interest to the other three noble houses. For thousands of years, every action they took had been dictated by tradition and strict rules. And so, with the birth of a son to the Kuchiki household, it was necessary to pair him with one of the daughters of the other houses. Both the Shiba household and the Shihouin household had daughters, but the Shihouin house’s daughter was the closest in age to the newborn infant.
Therefore it was decided that Kuchiki Byakuya and Shihouin Yoruichi would be betrothed. Yoruichi was still a child by Soul Society standards, but she was old enough to be skeptical of the situation.
“I have to marry who?” was her first question after her parents informed her. When her parents explained it further, she rolled her eyes. “No way! I’m not gonna marry some rotten little baby!”
After being scolded for her indelicacy, her parents refined their explanation to the extent that, while Yoruichi still wasn’t happy about it, at least she accepted it.
There was a small ceremony, which young Yoruichi found underwhelming. “Stupid snotty little baby,” she was heard to have said, after making a most ungraceful face at the cradle. Her parents made a mental note to tell her trainers to be stricter about what sort of language was used around their daughter.
As the newborn Byakuya grew, the interaction between the betrothed was limited. Byakuya was too young for extensive interaction with others, and Yoruichi was busy with her training, which was growing ever more intense. In fact, it wasn’t until Yoruichi was commander of the secret mobile corps that she found time to visit Byakuya and actually get to know him.
The relationship was rocky at first. The knowledge that they would have to get married at some point in their lives created an extremely awkward air between the two, especially since Byakuya was rather younger than Yoruichi.
However, Yoruichi had always been a very casual person, perhaps much more casual then she was supposed to be as a member of a noble house. This prevented her from letting the awkwardness get to her too much. She offered to help Byakuya with his training, and he agreed, reluctantly.
He later came to regret agreeing. Yoruichi’s methods of training were… unorthodox, to say the least. Maybe it was just because they were betrothed, but she teased him and played with him to the point where it drove him nearly insane.
But when he realized just how much better he was, at everything Yoruichi was teaching him, the regret receded, if only a little. And though neither of them were much looking forward to spending the rest of their lives together, they were at least getting used to the idea.
They grew older. Yoruichi’s position in Soul Society advanced further, to the point where she was both commander of the secret mobile corps and the captain of the second squad. She was recognized as the greatest user of shunpo, perhaps in history, and Byakuya came to appreciate her strange lessons a little more. He even slightly looked forward to the day when they’d be married. Maybe it wouldn’t be so bad after all, he thought.
Then… she disappeared.
Soul Society reeled in shock at losing not only the head of a noble house, but also several of its captains and vice-captains.
And Byakuya was left wondering whether or not the woman he was supposed to marry was even still alive. No one knew.
So he waited.
Without the presence of the wild and casual Yoruichi, Byakuya became more rigid, treating the rules of the noble houses and of Soul Society less as guidelines and more as cardinal rules to live his life by. And he grew in skill, though perhaps a bit less than if his teacher had still been around.
And he waited.
Eventually he became the captain of the sixth squad, and the head of the Kuchiki household. He was regarded as cold, ruthless, and unmerciful to rule breakers.
And he remained unmarried. He was still technically betrothed, after all, and it was still unknown whether or not his betrothed was even alive.
But one day he couldn’t wait any longer.
Because Kuchiki Byakuya had found someone he loved.
When Kuchiki Byakuya married Hisana, several eyebrows were raised, not only because she was a commoner, but also because he was finally deciding to consider his betrothed dead. That was, after all, the only acceptable way to cancel the arrangement.
And for a time, he was happy. Some might say he was still the same, but those who knew Byakuya could tell that he was happier than he had been in a long time, and perhaps the happiest he had ever been in his life.
But he still wondered, sometimes, whatever happened to the woman he was supposed to marry, all those years ago.