Chapter Text
Tobirama scowled down at the notes on his desk, still wet ink shining under the lamplight. Various tomes on ancient sealing were piled around him, notes and scrolls scattered in an organized mess that only he could navigate. The soft brushing against parchment was the only sound to break the silence of his lab, air as quiet and still as the night outside.
Technically speaking, his hiraishin had been completed years before, having been used even during the Senju-Uchiha war. He had started working on the jutsu as a child after all, first testing it just a few weeks after the loss of his second brother, though it had taken several more years of perfecting it before he felt confident using it in battle, and even then he used it sparingly.
Though that was its main use, he didn’t just use the hiraishin for combat. Shortly after the founding of Konoha, he had started using it for limited travel use, mainly when he didn’t want to deal with people outside of work. For a while he just placed a seal in his living room as an anchor, using it to quickly return home when he stayed late at his office or lab. After a few months of this, he eventually decided to place some more around the village, putting one in his office, his lab, the northern and southern gates to Konoha, and even in his brother’s house.
After a year or two of traveling in such a fashion, he finally realized that, while the hiraishin was excellent at short range, it was inefficient as a means of longer-distance travel - at least, as it was at the moment. Though it got him where he wanted, and, most importantly, when he wanted, the chakra cost used when compared to the distance traveled was utterly ridiculous.
So, being sure to leave the battle version as it was, he had started working on a version of the hiraishin specifically formatted for travel, playing with the seals and tweaking it here and there. It quickly became his one reprieve from constant fretting and what was essentially war preparation.
It had been three months, one week, and five days since Madara had defected from Konoha, and every second of Tobirama’s day stretched on and on. Unease prickled under his skin, keeping him twitchy and paranoid, itching for the comfort of a sword gripped in his hands. He recognized it was unhealthy to be on edge so often, and found comfort in the familiar safety of his research.
What started initially as just an attempt to lower the exponential growth of chakra cost over long distances had soon turned into an inventor’s playing ground. There were so many areas he hadn’t considered at first, so many possibilities that had been far from his war hungry mind when he first invented the Flying Thunder God technique, too focused on killing to see the every day uses. For a few manic hours, the scientist had found himself frantically jotting down idea after idea, ecstatic to find inspiration in something again.
Now, after several weeks had calmed down the initial influx of joy, he honestly just wanted to set his lab ablaze and never look back. There were just too many possibilities, too many things he wanted to do all at once.
The pale man groaned, scrubbing his face with calloused hands. His research lay in haphazard piles, to help organize his thoughts, but so many areas overlapped that it was useless trying to separate them. He was working on the Travel Distance aspects at the moment, trying to expand how far away the seals could activate together, but every time he changed something there he had to spend hours on the Chakra Consumption components. All of this always led to triple and quadruple checking of the Time Distance parts - the last thing he wanted was a repeat of his first hiraishin disaster, where he’d disappeared for nearly a week - and these three layers were only the basics, the lowest tier of what he was making.
And this was just one of the directions he wanted to take the jutsu in.
Red eyes peeking through long fingers, he glanced over at the clock. Two am. He sighed heavily before abandoning his work for the night, standing up and stretching. A flash of hand signs and he was home, heading down the dark hallway towards his room. He was to meet with Hashirama in the morning, and needed at least a few hours before facing his brother.
After a quick breakfast of leftover plain rice-and-seaweed onigiri, Tobirama flashed to his office at the hokage tower, avoiding the early morning rush in the streets below. He made his way through the hallways quickly, nodding a brief hello to Hyuuga Rin, not at all surprised to see the woman burying her nose in paperwork at such an hour. The Hyuuga were known for their punctuality and serious work ethic; their clan head was no exception to this.
Finally arriving, Tobirama gave a shark knock on the wood door before entering the hokage’s office, not bothering to wait for a reply. His brother sat behind his desk, quietly scanning a document, the bags under his eyes suggesting little sleep. Neither spoke a greeting, the younger settling himself into the oak chair opposite the desk, waiting in silence for Hashirama to address him.
There was a time, only half a year ago, when the silence would have been welcome, comfortable, between them. Now it only felt wrong. Despite working in the same building, despite living across the road from each other, they hardly shared a word anymore, even for business. When they did, it was strained, off.
Tobirama had only been here for five minutes, and he already wanted to go home.
At last, the older Senju put his scroll down, picking up a mission file to hand over. “You’re needed in Tea Country. Leave Friday morning at the latest.” A wave of a tawny hand, and he was dismissed without a glance from his older brother.
Hashirama never looked at Tobirama anymore, not really. Even when their eyes met, the older man was looking past him. It felt as if Tobirama was constantly being judged - and always found lacking.
Even still, Tobirama paused at the door, white fingers tight on the handle he hadn’t yet turned. It had been over three months. He knew he hadn’t really been there for his brother, not really knowing how to comfort him in person. He’d done what he knew how to, had taken on all of Hashirama’s duties when the man couldn’t drag himself out of his house for nearly three weeks in his grief. Was that not enough? Should he have done something more? Whatever this was, this tension between them…
“Did you need something?” He met his brother’s umber gaze. Couldn’t read the emotions there as he used to, couldn’t tell what his brother was thinking. His brother, who was always so open and warm, carefree, accepting of everyone.
His brother, who looked at him as if he were not there, as if he shouldn’t be there.
“Nothing, Hokage-sama.” He left quietly, not bothering to wait for a response. He knew he wouldn’t get one.
Not wanting to spend the day in the tower, Tobirama only dropped by his office briefly to pick up any urgent paperwork. He had made a habit of this recently, only staying when absolutely necessary. Most anyone who would need him knew to leave a message, and if the matter was urgent, they could reach him through his brother.
Since he never had trouble keeping up with his work, there was only a small stack of documents needed done by that afternoon, and only about a dozen others that would need to be done before he left - all in all, that was only a few hours work for him. If he was leaving Friday, that gave him three days to prepare. And - he ran his eyes over the mission details - it would really only take him an hour to do so Thursday night.
Arriving at his lab after a flicker of hand seals, he sat back down at his desk, preparing his ink and brush, working through his work quickly before going back to his own project. Going all the way to Tea Country gave him the perfect opportunity to test the distance of his travel-based hiraishin, but he needed to spend as much time as possible working on it beforehand. The chakra cost of the original over that distance was vastly more than he could ever afford - it would kill him near instantly.
That being said, of what he’s changed, it might not kill him. Might not.
The main concern at the moment was how consistent the chakra cost would be. Since it was primarily used in battle, in a relatively small area, it was originally difficult to measure how much the chakra cost increased over distance. For shorter distances, it remained relatively the same - or, at the very least, the cost increased at consistent increments. He had been attempting to make distance a non-factor in how much chakra was consumed by the jutsu; and, if that wasn’t difficult enough, trying to also keep the chakra cost at a reasonable level was honestly nightmare fuel at this point.
By the time Thursday rolled around, Tobirama wasn’t that much closer to an on-paper solution, let alone one safe enough for field study. After a quick breakfast of rice and miso, he went back to his lab anyway, fully expecting another day of disappointments.
When a solution finally hit him, he was near angry that it hadn’t occurred to him before.
Chakra storage seals.
He jumped up from his slumped position over his notes, nearly sending his chair flying in his haste, rushing over to the bookshelf on the far wall. Chakra storage sealing was one of his favorite fields of study, making up nearly an eight of his collected tomes on sealing, and it was something he had considered including in a version of the hiraishin previously. At the time, he had been wanting to create a fail safe for shinobi on out-of-village missions. The idea had been to have a secure and heavily guarded base anchor in the village, and all active Konoha shinobi would have a hirahishin seal with them that, if activated, would transport them to the anchor instantly. On top of that, to counteract the potential of low chakra in the user, the chakra storage seals worked in would have enough stored to transport up to two people.
Of course, after Madara’s explosive exit, Tobirama had put that project on hiatus. As useful as such a thing would be, it also posed a potentially major security risk if in the hands of enemy nin. He’d put both the blueprints and proposal away to collect dust indefinitely.
But, if he used the storage seals here…
He flipped through the yellowed pages, pacing behind his chair while skimming over the previously marked margins, his own notes refreshing his mind on the subject. Even if he couldn’t lower the chakra cost much more, even if he couldn’t keep the cost consistent over the distance, he could use stored chakra to keep it from killing him.
He sat back in his chair, inspiration reignited as he got back to work. It would be tricky still, risky even. He would need more than one fail safe built in. If he had the seals auto deactivate when the user’s chakra was too low, and if the storage seals flowed directly into the user afterward…
By the time he slumped down onto his futon that night, he was beyond exhausted, and only had four hours to sleep until he left. But he found himself near giddy with anticipation and pride, something he hadn’t felt in nearly a year.
His new hiraishin just might work.
Not even the dull nature of his mission could bring Tobirama’s mood down. He was to represent Konoha’s interests at a meeting with Tea Country dignitaries - really, he was there more as a threatening presence than anything else. Konoha had no issues with their proposals, nor any further suggestions for the non-shinobi villages. He did have to dodge some rather insistent marriage proposals, but, as the current heir to a rather powerful and well-known clan, he was more than used to it by then.
Finally, after six days of non-stop meetings, led by people who honestly couldn’t talk themselves out of a sake keg, it was time to test his improved jutsu.
As he sat in his hotel room preparing his mission report, he thought, in passing, that he should really name this travel-based hiraishin something other than “the improved hiraishin,” but, ultimately, decided that was a thought for later.
Though he believed this was a relatively safe test, in comparison to many jutsu before that had unsurprisingly landed him in the hospital a few times, he still wanted to send his report in separately. With a quick bite to his thumb and a pulse of chakra, a young leopard appeared in a puff of smoke.
“Hanten,” Tobirama knelt down in front of the feline, fondness already softening the edges of his face as she loudly demanded attention. She was roughly twice the size of a domestic cat, and was one of his lesser summons, but one of his favorites nonetheless. She practically vibrated with how aggressively she purred at him, ramming her head into his palms and licking his fingers. He scratched behind her ears, feeling a moment of guilt for not calling on her more often. “I need you to take something to Anija. Can you do that?”
Being unable to speak, she nodded vigorously at him, bumping her head on the outstretched scroll before taking it gently between her teeth. Instead of leaving immediately, she forced her way into his lab, refusing to budge until she was thoroughly spoiled.
As he watched her leap out the window, the black tip of her tail flickering out of sight, he made a mental note to spend more time with her. He had been there when she had been birthed only a few years ago, and had bonded with her near instantly - had carried her everywhere for a few months, both refusing to leave the other’s side. He missed that companionship.
Getting back to the task at hand, he gathered all of his supplies, running over his mental check list several times before finally, finally, he was ready. He pulled out a slip of parchment, black ink already marking the seals, previously stored chakra buzzing at his fingertips. All he needed to do was concentrate on the desired anchor location, press his chakra into the seals…
A deep breath. Excitement and adrenaline buzzed under his skin, the start of a grin pulling at his mouth, eyes wide. This was it.
A pulse of energy, and he was gone, stretching towards his destination.
Because of the nature of space-time jutsu, though it happened near instantaneous to any onlookers, the user always perceived a passage of time. It was, after all, the act of traveling through both space and time, not just one or the other. And, over longer distances, time seemed to stretch further and further, despite no recordable effects on the jutsu user.
Over nearly a whole country, time stretched to near eternity. Tobirama had no way to measure his experience, but he knew it had never taken so long before - of course, that was to be expected. This was the furthest he had traveled via hiraishin after all; his current experience with the perceived passage of time was of no concer.
His rapidly depleting chakra, however, was rather concerning.
Just as he thought the fail safes might have, well, failed, and he might die from chakra exhaustion, he crashed into what he believed to be his brother’s living room, arrival sending him flying into several pieces of wooden furniture without warning.
As he lay on his back, gasping at the sudden and intense pain on the back of his head, vision swimming, he had a brief moment to realize that this wasn’t where he meant to teleport.
Then, his vision went black.
The sharp smell of anti-septic was the first thing he noticed, followed shortly by how ungodly bright the room was. He blinked his eyes open, squinting up at the unfamiliar ceiling, trying with little success to remember how he had gotten here. His thoughts were muddy, and he could only recall hitting his head hard against something after using the hiraishin.
He hated head injuries.
Groaning loudly, he started pushing himself up, a thin white sheet slipping off of his torso - then strong arms were helping him sit up, and a rather distraught Hashirama was suddenly fretting over him: checking his pulse, his breathing, pressing warm fingertips near his head injury, a thousand questions shot at him like rapid fire.
Since his thoughts couldn’t quite yet keep up with his brother’s frantic questions, he merely blinked up at the man, noting his wet eyes and overall frazzled appearance. The behavior was in direct contrast to what he’d been experiencing for the past few months - I.e. avoiding Tobirama and not speaking to him unless absolutely necessary - the change definitely not warranted from what he assumed to be a minor concussion.
He was reminded once more of his first attempt at the hiraishin, just a few short weeks after Itama had been buried. How he had activated the jutsu and not reappeared until six days had passed, returning to a furious and concerned Butsuma and a sobbing brother.
By the similar panicked look in Hashirama’s eyes now, he could only assume he’d messed up again.
“How long was I gone this time?” A pause, the slurred question hanging the air between them, and Hashirama broke.