-The Probability of Nothing-

Created for the prompt: Gin/Zura soulmates, childhood best friends; cross-posted from Tumblr.

Gintoki was still in a sleepy haze, his neck throbbing from his bad sleeping position on the couch when Kagura shrieked.

Looking up, he followed the young girl's gaze to the door. Gintoki sat up in alarm, the boy's expression pained as one hand gripped his arm, blood seeping through his white sleeves.

"What happened?" Gintoki scratched his head, getting up with a yawn. "Did you trip over the stairs on the way here or something?"

Shinpachi didn't respond immediately as he settled on the couch opposite, Kagura running in and out the room for bandages.

"I'm not too sure, when I brushed passed a large crowd out the local market it, my arm suddenly started hurting. When I looked at it, it was bleeding…" Shinpachi frowned. "Maybe I just accidentaly brushed past something sharp."

Gintoki raised a brow, his hand reaching out. "Show me."

Kagura had almost washed off most of the blood by now, leaving only a black mark growing on the young boy's forearm.

Gintoki grinned, "Idiot boy, you've found your soulmate."

Shinpachi answered only with silence, staring in disblief. It left Kagura to look between the two of them confusedly, "What? What? What soulmate?"

Gintoki raised a brow, "Not sure if it works for you, but the first time a person touches their soulmates after they turn 18, their arm bleeds out, leaving behind a black insignia that is identical only to their soulmate. Now Patsuan's just gotta find the one."

Kagura paused, silent and thoughtful, before she looked up again, her eyes glittering.

"Do you have a soulmate?"

Gintoki froze, his heart sinking. Of course the girl would mention this. He turned to walk away, only fro the girl to grip his sleeve, pulling it up.

"So even a hopeless guy like you have a mark!"

Gintoki glared as the young girl only smirked. "Tell me about them! Who was it?"

Gintoki sighed, his fingers reaching up to massage his forehead. "Back then, no one had any time to worry about soulmates or the insignia. I don't even know when I got it - I was still in the war when I was 18, who could tell what blood and what pain was from where? I only noticed it aftewards, but it's too late then. For all I know, they could be dead already, or from the enemy side."

Kagura nudged at him, "Don't you think there could have been one? At least one person in the war who you felt closer to? That just pulled you towards him?"

Gintoki hesitated, a lump forming at his throat. "No," he replied. "There wasn't."

A week later, Otae held a celebration at the Dojo.

Waiting by the market place had brought Shinpachi luck, and once Shinpachi's propsect had been found, everyone had been quick to bring her in. Creeped out more often than once, it seems Shinpachi's soulmate has an equal knack for playing the tsukkomi role. The noise and fervor was exciting, and the free alcohol, although mediocre, was still better than the quality he usually had. But before the party had even climaxed, Gintoki found himself outside. He sat by the small rock pond, listening to the Sozu break the empty silence every once in a while.

Footsteps alerted him of another prescence, faint on the grass but not subtle enough to be sneaking. Gintoki closed his eyes, sighing; he had familiarised himself with these footsteps years ago.

"What do you want, Zura? The party's inside, you know."

"It's not Zura, it's Katsura," The reply was automatic, but the usual zeal was absent. "And I wasn't invited; the Shinsengumi commander is in there right now."

"That's never stopped you before."

"Well, the party isn't where I want to go right now," Katsura continued. He found a spot next to Gintoki, and sat down cross legged.

The remained as they were for a long moment, neither talking any further. Gintoki stared at the pond, squinting at the flashes of red or white of the fishes despite being too dark to make them out properly. Zura looked skyward, his two hands on the ground, supporting behind him as he leaned back.

"This whole soulmate thing is so bizarre, you know. If it weren't for the sign, perhaps two people might not have even liked each other." Zura commented at last, a casual air covering the tension in his tone. "So much of this whole soulmates idea lies in the mind, and yet it is also the mind that stops two people who are not soulmates from getting together; the idea that it's not right…"

"That's stupid," Gintoki snapped, interrupting. "This whole idea of soulmates - it's all in the mind. We should just ignore it."

"You didn't think that way back when we were kids," Zura retorted numbly, Gintoki blanched.

Averting his eyes, Gintoki's voice was quiet, "We were idiots back then."

"What have we got to lose, honestly?" Zura demanded. "Whatever our marks are, it wouldn't be that different to how you're treating us now - what are you so afraid of? Just show me yours, or let me show you mine."

"No."

"You promised, back then, that the day you turned 18, the first thing you would do is to hold my hand. The war happened, that's understandable, and we had touched so many different people, some still living, many dead by our own hands, it's true it could have been any one of them - but it could also be me. Why must you keep denying that?"

"…" Gintoki remained silent for a long time, before replying, "Because if it isn't you - I don't know what I'd do."

"Fine," Zura's voice suddenly hardened, the Joui getting back on his feet. Gintoki looked up, expecting him to march away, only for Katsura to lift his arm directly before him. Gintoki winced, expecting a completely foreign insignia - the telltale sign that they were not meant to be. But instead, it was a black splotch, the whole arm decorated in a large, black patch. Zura's voice softened, "This way, you will never know. It could be, it might not be, but either way, you can't tell me I'm not yours."

Gintoki rolled his eyes, "Idiot."

"You know what they always say, Gintoki; take the benefit of the doubt." With that Zura walked away, from Gintoki and from the light of the party, away from Otae's dojo.

Gintoki watched him for a long moment, before he closed his eyes, his head buried in his hands. He could follow Zura now, or go back to the party and pretend, as he had always done, that nothing had happened. That nothing was wrong. He thought, and sighed, and weighed his options, before he made his decision.

Later, when Kagura came outside to call Gintoki home, he was no longer there.