The "Yachiru" referenced here is the first Yachiru.
Summary: As a line goes: "parting is such sweet sorrow."
And The Heavens Parted
It was hard to see him walk away. Deep in the back of his mind, he knew that it would come down to this, the parting.
Shinigami were always on constant alert for hollows, always training to better themselves, minimize the risk of getting killed in the line of duty. But, despite how much work they did, how often or hard they trained, there still lay the risk of being killed. There was always a stronger, more powerful force, lying in wait and waiting to jump at an overconfident shinigami.
If they ever were to part, Jushiro would want either one of them – preferably both so that the other wouldn't have to be left alone – die on the battlefield, going down in a blaze of glory. There was honour in sacrificing for what one held most dear. Jushiro – he fought for the Seireitei, for his division, for him. Dying for his sake was just one of the prices Jushiro was willing to pay to leave Soul Society.
But then there he was, standing frozen to the spot, unable to even move his numb limbs. The soft sound of jingling bells drifted on the breeze, coming to settle on his ears. They used to be calming, those odd jingles, but now all he felt was dread. With each step the man took away from him, the sound grew quieter, more distant. His captain's haori, ragged-hemmed and wrapped around his large figure, billowed out from behind him. That haori Jushiro used to snuggle in during cold nights, inhaling an earthly scent unique to its owner. That haori he had taken upon himself to wash, ignoring his maidservant's protests at his emaciated being taking over such chores. The haori that hid sun-tanned, scarred skin he used to kiss.
Jushiro shook his head, unable to accept such an abrupt choice. A sudden halt to their long relationship. He forced his feet to move, taking one step at a time, difficult as they were still numb from shock.
What a great start to the day, he mused bitterly. Gradually increasing the speed of his pace, he finally mustered up the courage, the strength to call out, "Zaraki!"
He didn't stop, didn't even make a move to turn around at his name. He kept walking, as if he hadn't heard the summon, like he was deaf. Jushiro, biting his lower lip, ignoring the pricking at the back of his eyes, reached out and grabbed his wrist.
"Zaraki, what in the gods' names are you doing?" he demanded, gritting his teeth. Kenpachi, silent, merely raised his face to the sky, an indecisive expression carved out on his face. In all those years they had been together, Jushiro had never seen him like this before, torn between two options. And what made it worse was that he had no clue as to why he was drawn to such a choice. The man was known to be rash and violent in nature, but through his actions today, he had taken it to a whole new level.
"Look at me, Zaraki." Jushiro clutched his sleeve, but was unable to even make Kenpachi budge. "What's wrong? What happened?"
"I…" He looked even more lost, interest stolen by the vast sky, and his next words chilled Jushiro to the bone. "I told her that I ain't gonna forget 'bout her. I promised her."
Jushiro knew exactly who he was talking about. His grip on Kenpachi's sleeve only tightened, afraid but already knowing what was to come. It was only after a while of bitter silence that he let Kenpachi go, hands falling back to his sides, head lowered in defeat. On occasion, when the large man had loosened up a little from the awkward sense of being with Jushiro, he had been fed little snippets of Kenpachi's life before the Seireitei – how he met Yachiru, experience in the 80th District, the child Yachiru's namesake, the only person Kenpachi ever admired…
"Right," Jushiro murmured, trying not to choke on his own words, "you…you don't want to break your promise."
Silence.
And when Jushiro looked up once again, Kenpachi's back was a ways in the distance, haori billowing about his large frame. The sound of bells was gone, and oddly enough, Jushiro missed it already. He squeezed his eyes shut, trying in vain to control the vicious pricking at the back of his eyes, a sentiment that never really hit him until now. He did feel it upon the passing of his parents, of Kaien, when he was holding his dying comrades in his arms.
But it was never as bad as this.
A hand crept up his chest to grasp his uniform, over the area where his heart thundered against the walls of his ribcage.
Am I not enough?
Jushiro didn't know many things. Questions swirled around in his mind, tripping and tumbling over one another, driving him to the edge of sanity. It was hard just to keep up with them, and eventually they dragged him down to his knees. He hit the ground with a shaky expulsion of breath, numb to the pain that shot up his knees upon impact.
It was only when the heavens parted that Jushiro allowed his tears to fall, but they mixed with the cold, fresh rain, and he couldn't tell whether the gods were crying for him, or for the late Yachiru.