Born into the Hayabusa clan with his twin Hikari. They both showed immense promise for a Clan that didn't come from the nobles. Kurai himself was born and seemed to have a world around his fingertips. Kurai was the name he was born with and acknowledged as his own at the time. His mother named the brothers the light and shadow. Kurai would always follow Hikari where he went. Despite the differences between the two, Kurai did showcase a tremendous talent for the clan's techniques. Able to perform telekinetic kido for a flight at a young age. The boy spent much of his time practicing with Hikari and training himself relentlessly. Hayabusa was known to be warriors and samurai-like beings. The training involved different things, being forced to climb up cliffs. Or swim up waterfalls or levitating heavy rocks while avoiding blows. This was the life Kurai and Hikari were born into. The parents weren't strict nor were they easy. Typical parents who trained their children for better days. Those brothers fought and ran simulations of the ever possible outcome. Kurai was the first one to learn and utilize his zanpakuto before Hikari. The brothers began to make a gap between one another slowly as the cheerful one got further. Kurai began to distance himself from Hikari. It wasn't long before he caught the attention fo the Gotei. He'd stopped a group of bandits and handled cleaning up some parts of the Outlands. Bringing in criminals who were being bad as he put it. Years could flow like rainfall from here as Kurai's life and time were spent training under a single person. Tsubasa Unabara had come to call on the Hayabusa for the Soul King. A Master of Void was needed, this position didn't require much. But it was noted Kurai was the youngest to enter the Palace at the time. He'd proven himself a versatile child in most cases. Disappearing to handle a situation that few others could manage. The Keeper or Master of Void could be best described as the person fighting hollows. His duty was to guard the King against anything that would do harm.
To keep those not worthy of entering the Palace and defeat them before others. The first line of defense against the Menos Grande was a small child. Kurai quickly adjusted to his title and duty embracing it. It wasn't long before his brother joined him also as a goal. The two were during a period where the hollows made little progress. Slaying over one thousand Menos Grand of varying forms and births. Kurai had become a true Reaper in this sense. His training under Tsubasa was the worst part of his time there. He spent his day learning swordplay and how to fight strategically. Though being but a child and wanting to have fun in this world around him. He didn't understand the darkness that lingered outstretched. That this job required him to combat demons and hellspawn who'd attempt the vilest of things. The training was about control and understanding his powers purpose.
Sadly things wouldn't always be this way. As upon Tsubasa's departure, Hikari and Kurai were left alone within the Grand Palace. Guarding against the coming enemies with no aid or support. That place the King had them guard never seemed to tire. Each day it had been a never-ending struggle. Kurai and Hikari were well trained and capable of combating them. But they were childish and youthful perhaps naive in the truest sense. The shadow lost his light one day and so much more. Kurai's journey didn't have rises and falls or much to it. Training and following after Hikari were it. But when Hikari died, he lost sight of so many things. His brother had protected him as he'd always done. Sub coming to injuries in the field. Kurai remained and fought alone for hundreds of years. Facing down enemies in this place as directed never getting orders. This would be the place4 he died like his brother. Kurai had made that his ultimate goal at this point. He'd fight till he collapses and fights again. Death was the only sweet nectar he required from this world.
But as time marched on and hundred of centuries passed. Kurai's injuries grew and the cheerful child had died. He'd lost most will to communicate or even do anything. The Shinigami who once had been the bright sun that could light up anything. Had been broken and battered, his mind and soul had been almost obliterated from constant fighting and violence. This location was never given out to others as it was considered too brutal. The Zero Division had exclusively watched over it. Kurai had been the last one to keep it and do his duty. So he lingered here broken and bleeding as his zanpakuto had been shattered. He'd been fighting them this time with broken arms and other damages. He'd truly given his body and soul to this purpose. If not for an intervention, nothing would have remained. The boy who once smiled may have died that day. But his journey in this world would go on thanks to Tsubasa's intervention. He'd continue his journey towards a new path.
That new path began after something touch and go of course. Kurai had died in that shadowy world the Soul King had them, guard. His body had been broken and his spirit mangled. Tsubasa's rebuilding of Shiro began now as the boy was put into a new body. The loss of his zanpakuto and body didn't matter much. It wasn't a difficult beginning to mark as this didn't come without scars. Shiro's birth saw the death of Kurai the boy who broke everything to die with his brother. Shiro didn't get to keep anything but some muscle memories. His memories aside from that were damaged badly. Beyond repair to some extent, as the boy who previously served had been lost to the darkness he once embodied. Shiro didn't have access to that or even known of the Hayabusa. No name or purpose really exists for him. Shiro was strong still and did maintain some level of power he believed. His Martial Skills were still potent and able to be understood as such. But this was a new beginning one that foreshadowed a darkness in his future. Or perhaps a frozen path of nothing happening. But this month of being reborn into a Doll had done nothing for the broken male. Shiro had simply lost too much in the process to care or acknowledge caring. His body and heartfelt numb. Perhaps even his soul had gone numb in the process of this entire thing. While he is grateful to Tsubasa for whatever he did. Shiro cannot shake an unease from his chest. That sometime long ago his purpose and the music in his heart died. He feels no desire or hunger for anything in this world. The meaning has been drained for him and as he awakens to venture another day. This world is nothing but an abyss for him to walk through. He stumbles through the area unaware and damaged. Perhaps a forgotten relic of a time forgotten. His days now spent staring blankly into space and trying to claw desperately for something to go on.