Lorentz Factor
The sombreness that had befallen the Senju compound for the past few weeks is lifted at last with the news of their clan heir’s impending return. How could they not rejoice? Tobirama is beloved by his people after all.
Hashirama is their clan leader and representative of their most cherished honour with his potent gift for creating life. He is strong-willed, just, and flexible in his ways. He is of open mind and heart, happy to embrace new ways if they are for the better, and a patron of the arts and sciences much like his grandfather had been.
But their clan heir is a creator of a different kind with his seemingly unquenchable thirst for invention. It is Tobirama who is credited with optimising their irrigation systems and establishing the rigorously efficient way of administration that they are subscribed to currently. He is the one whose strategies they adopt for their attacks, and it is his optimised healing techniques based upon mokuton that have improved their chances at survival.
Tobirama’s ruthlessness is not frowned upon in a clan that has only ever benefitted from the protection it offers. Now that he is due to return, they look forward to the retribution he is sure to seek for them.
Hashirama thinks it might be easier this way.
He is unsure if he could ever take that step by himself, too absorbed in the conflict between his duty and his desire, but he knows his brother will not hesitate in the same way. Tobirama has shaped himself at Hashirama’s side, built himself up to make up for his clan head’s shortcomings so the clan never has to suffer for it. With no idea of where to go from here, Hashirama is perhaps selfishly eager to let Tobirama act as his compass once more.
He thinks the desperation must show on his face too because Tobirama is uncharacteristically tolerant of the way Hashirama gravitates towards him before he has even fully managed to disembark from his horse, shoulders loose under Hashirama’s hands, allowing himself to be pulled close and held gently regardless of the many eyes upon them.
“You are creating a scene, anija,” Tobirama admonishes quietly only for Hashirama’s ears, though it is notable that he does not push his brother away or try to struggle.
Hashirama steals a moment longer of comfort, feeding his greed when it seems like Tobirama is feeling generous today. “Let them stare,” he says defiantly. “Everyone here surely knows by now you are my only weakness.”
It is entirely unsurprising when Tobirama rolls his eyes at that and pointedly disentangles himself from Hashirama. “Well, they are all certainly aware now if they hadn’t been before,” he drawls. “I hope you’re happy with yourself.”
And Hashirama can only laugh at that, so relieved for the familiarity of his brother’s nagging. “Indeed, I am. It is good to have you back, Tora. I have missed you sorely.”
Tobirama’s eyes soften. “I am pleased to be back, anija,” he returns gently.
He must mean it too if he is going so far as to excuse and ignore the use of the childhood nickname that had been put out of use because their father had disapproved of such blatant softness and informality from his heirs.
“Minakami-dono had nothing but praise for you in his letter,” Hashirama says, leading the way down the streets of their home, absently nodding in return to the greetings they are offered as they pass through, “and we have all heard of the waves you have been making in the capital with your work at the Academy. You have truly done well over the course of your trip, Tobirama. We are all very proud.”
Humming, Tobirama eyes the remainders of ongoing reconstruction, an unreadable expression on his face. “But perhaps we would have all been better off had I stayed,” he comments grimly.
Hashirama swallows and tries for a smile that he knows falls flat. “I will not lie; we certainly could have used your aid. However, it could not be helped. You were needed to solidify our ties with the Uzumaki, and you have been a credit to the Senju name regardless.”
Tobirama inclines his head and allows his chakra to brush briefly against Hashirama’s in an easy and private show of comfort. “How have you handled the aftermath?”
“We fortified our defences first. Patrols have been increased and sensors are stationed at every checkpoint for regular monitoring. The damage to the compound has been mostly rebuilt, and most of the civilians have been moved back to their homes. I personally arranged for the funerals of those we lost.” Hashirama sighs and ushers Tobirama up the steps of their engawa and through the doorway, sliding the doors shut behind them. “The people…are restless. Afraid. Angry.”
His brother does not look surprised. “I imagine the elders have begun to demand you take charge.”
Lips pursed at the reminder, Hashirama admits, “Yes.”
Studying him carefully, Tobirama asks, “And will you?”
“I do not think there is much of a choice,” Hashirama points out, toying with the edge of his sleeve. “We will risk mutiny if I allow this to pass.”
“Yet you are hesitant,” Tobirama observes, tone too neutral to allow Hashirama any interpretation.
“I can’t help it, Tobirama,” Hashirama tries to protest, avoiding his brother’s gaze. “I do not wish to involve the clan in another fight, and I find no value in revenge.”
He is already half expecting an argument to erupt. Tobirama has never understood Hashirama’s hesitations when there is such a clear decision to be made, and he has certainly never shied away from doing whatever it takes to ensure the optimal outcome.
“They will never accept allowing this to pass,” Tobirama states. A palpable frigidity enters his voice as he adds, “The Uchiha attacked our home unprovoked. That is unforgivable.”
Hashirama closes his eyes. “I know.”
“You are still uncertain,” Tobirama says knowingly. He sighs and turns away. “Regardless, you were right about there being little choice in this instance. We have suffered enough loss with the damages we incurred as it is; we cannot risk losing our clientele over what will be perceived as cowardice. Not when winter is almost at our doors and there is little other source of income for our people. Retaliation is the best option.”
None of this surprises Hashirama. He had expected Tobirama would cut right to the heart of the issue and assume this stance with his usual no-nonsense efficiency.
He sighs. “You are right,” he admits, biting his lip. Though he has been raised upon traditional Senju values of strong wills and unfaltering inner truth, Hashirama is more importantly the head of a shinobi clan, which means that duty must come first for a man of his position. He cannot forget or outrun this fact. “It just never gets any easier.”
For a long moment, Tobirama is quiet as he watches Hashirama, something pensive in the set of his mouth. “I know,” he says after a pause. “You have always been too soft that way.”
Hashirama flinches at the callous observation, unsure of how to respond.
But Tobirama is sighing and looking away, clearly not expecting one. “I suppose you wouldn’t be yourself without it though,” he adds, almost as though to himself, wandering off into the kitchen where Hashirama can hear the telltale sounds of him starting to prepare some tea.
He blinks where he is left standing in the genkan, caught off-guard by the simple dismissal when part of him had already begun preparing for hurt.
It is odd. Not unpleasant in the least, but still odd. This softness that Tobirama seems to have found—or rather rediscovered—since his catastrophic mission all those months ago. The incident has changed them both, Hashirama knows. Still, he is disarmed by his younger brother’s smoothed edges and consideration, reminded of the fleeting peace they had been allowed in their early childhood.
Tobirama had been so free as a child, tactile and fierce in his love just as his mother had been. He had spoken his mind plainly and bared his teeth at the world, stubbornly clinging to Hashirama no matter how hard anyone tried to separate them for their lessons. His brother had been such a wild thing in fact that their father had ended up sending him off to the shrine to be tamed despite Butsuma’s strained relationship with them. By the time Itama was born, Tobirama had already become a much more formal and sombre boy thanks to his early education being left to the chief priestess.
That isn’t to say Tobirama lost his vicious way of loving; the marks on his face will remind Hashirama of that every time he looks at his brother. But he certainly learned to guard his heart well. Too well, in Hashirama’s opinion.
To have his brother let down those barriers if only a little bit, to be allowed this gentleness again—it is valuable.
It does not feel like forgiveness, and it certainly does not erase Hashirama’s guilt or conflict regarding the plans they will have to form to deal with the Uchiha soon. But—
Well, with half this burden lifted off his shoulders, it certainly has become easier to carry.
“It is a relief to have you back healthy and whole from your trip, Tobirama-sama,” Elder Kaname says, personally pouring Tobirama’s cup of tea before offering it to the clan heir.
Tobirama dips his head and accepts, carefully keeping himself from raising his brows. ‘Relief,’ he thinks, wrapping his fingers around the warmed ceramic. What an odd choice of words. He wonders if it is intentional.
“I only wish I could have returned sooner,” he says in response. “We might have been spared some of our losses had I been here.”
Kaname hums. “You can hardly be blamed.” He glances at Tobirama over the rim of his cup and adds pointedly, “The fault lies solely with the ones who attacked us.”
“It was a vile deed even for the Uchiha,” Tobirama agrees easily.
“They grow bolder by the day.” Kaname frowns, turning to look out the window. “I fear to think what would happen should we be caught off guard by whatever they might do next, emboldened by this attempt.”
Following his gaze to the Senju’s Sacred Tree in the distance, Tobirama makes a soft sound of agreement. “An escalation to this degree should not be ignored.”
Wryly, the elder notes, “Our honourable clan head is a merciful man.”
“Yes,” Tobirama agrees, “such is his nature.”
Kaname turns back to him, eyes sharp. “You have always been wise beyond your years, Tobirama-sama. Your late father praised your insightfulness often. Our current clan head is much the same. He values your counsel above all else.”
Unfazed, Tobirama sips at his tea slowly, savouring the earthy bitterness. “We have spoken,” he admits in response to the subtle prodding.
“I am glad. Hashirama-sama insisted upon waiting for your return to hear your opinion.”
Smiling in faint amusement at that, Tobirama acquiesces, “Anija is very considerate of me.”
Kaname’s eyebrows rise ever so slightly. “It is to be expected,” he says. “He is fortunate to have a trustworthy advisor in you.”
“I am the fortunate one, Kaname-san,” Tobirama corrects, setting his cup down, “that my clan head has such faith in my regard for our clan.”
There is a lull wherein Kaname watches Tobirama with unreadable eyes. Tobirama meets his gaze evenly.
Finally, the elder says, “You always have done what is best for the Senju name.” It is an observation.
Tobirama inclines his head. “I am simply doing my duty.”
“And what is your duty, Tobirama-sama?”
Unflinching, Tobirama replies, “To ensure the continued vitality and prosperity of our people.”
“We have been dishonoured by this tragedy,” Kaname states seriously. “The Uchiha have made us out to be victims. Weak. It is a taunt.”
“It is a challenge,” Tobirama corrects plainly, “and we will not shy away from it.” Pointedly, he adds, “There is a time and place for mercy, but duty comes before all. The Senju will be no one’s victims.”
The line of Kaname’s shoulders relaxes ever so slightly, and Tobirama watches it happen with interest. The elder refills both cups and sits back in his seat. “Your father’s high regard of you was not misplaced, I see.”
“I am honoured by your assessment, Kaname-san.”
Elder Kaname smiles. Tobirama does not bother smiling back.
“What will we do when the Uchiha inevitably respond to this clash we will initiate?” Hashirama asks quietly when they are both in his study, poring over a map of the surrounding forests to begin planning. He is not asking with the despondence of a remorseful man but with the severity of a commander.
In another life, Tobirama might have been irritated to be treated as though warmongering is his personal proposal when it should be his brother’s responsibility. In this one, he knows now that this is a role Hashirama needs him to assume for the sake of his own clarity and conscience; an obligation his elder brother will never don with the same ease as Tobirama.
And the question is a fair one. They need to consider how they will minimise their losses and prolonged battle is not conducive to such an undertaking.
“We should aim for as close to winter as we can,” Tobirama murmurs thoughtfully. “There is no precedent for them drawing conflict out to the season.”
“There was no recent precedent for them attacking the compound either,” Hashirama counters in a sarcastic drawl.
Mouth twitching, Tobirama acquiesces, “True.”
“Uchiha attacks are weaker in the winter because of their biology, but my mokuton is much the same. With most of the forest slowing down in the cold, our defence will be compromised. Perhaps we can rely on increased patrols, but I worry that might be taken as a sign of aggression and only result in smaller but more frequent clashes.”
“We need a different sort of defensive measure in place then.” Tobirama hums in thought. “Ideally, something long-term that will outlast the cold months.”
Hashirama watches him for a moment, a thoughtful slant to his mouth. Seemingly abruptly, he brings up, “I heard you had a meeting with Elder Kaname recently.”
“Yes,” Tobirama confirms, blinking.
“I saw him earlier today. He told me I am lucky to have an advisor like you by my side.”
Unsure of where this is going, Tobirama tilts his head. “I see.”
Hashirama’s face is unreadable. “He also said that father would be proud of us. Of you.”
Ah. Tobirama says nothing to that, waiting for Hashirama to speak of what is on his mind.
Finally, his brother brings up haltingly, “Father always believed that being on attack is the best defensive measure.”
Tobirama hums and considers this. “You are not that kind of leader,” he states after a pause.
“Would you want me to be?”
“No.” The answer is immediate and Hashirama looks almost stunned by it. “There is no one I would rather follow more than you, anija. There is no need for you to emulate father, and I would not want you to. You are a far better man than he ever was.”
That startles a laugh out of his brother. “You shouldn’t let anyone else hear you speak that way of your former clan head.”
Tobirama shrugs carelessly. “I trust you,” he says as if it is that simple.
The smile Hashirama rewards him with is a small, boyish thing. “I trust you too, Tobira.” He grows serious once more as he adds, “A long-term defensive system sounds like a good idea, especially if it can reduce our engagement with the Uchiha. Though I can’t be sure how some factions of the council will take to something like that.”
“We’ll just have to stress the benefits of reducing our contact with the Uchiha,” Tobirama concludes reasonably. “The less time and manpower we spend fighting these battles, the more we can direct those resources into taking missions that are more profitable to us. Spring is always a particularly busy time for our shinobi anyways. We could take on more prolonged missions that take us further away if we don’t have to always account for a minimum force that can fight in a potential skirmish.”
There is a note of surprise in the slight gape of Hashirama’s mouth as he stares at his younger brother. “I thought you hated the Uchiha.” When Tobirama raises a brow at that, Hashirama flushes and elaborates, “I just—I always assumed you wouldn’t agree to non-engagement with them.”
Tobirama turns to look down at the map spread out over the table, frowning slightly in thought. “I wouldn’t have,” he decides. “Not until recently anyways. It is difficult to rely on something like non-engagement when it isn’t backed by a contractual agreement between both parties. At least when we are both actively against each other, I know where they are and what to expect from them. I wouldn’t trust the Uchiha to uphold their end of an unofficial truce, and to be frank, I still don’t.”
“Then, why…?”
“Because I think they are holding us back,” Tobirama admits readily. “We would be stronger and wealthier if we didn’t have to funnel resources into a meaningless war. You have already set us on the path for that, and yet we are being held back once again by the politics of something with no net gain. It’s a waste of time.”
But Hashirama looks sceptical of that. Tobirama can’t say he blames him. At this age, he had been much angrier and warier, unable to put faith into something like peace because he simply couldn’t imagine how they could ever coexist with lifelong enemies. Now, however, with memories of their successful cohabitation, this conflict truly does feel pointless. Tobirama has fought wars of higher stakes and far greater magnitude; that isn’t something he can ever walk away from. The Senju’s bad blood with the Uchiha feels…juvenile by comparison.
“Is that so?” His older brother eyes him with something akin to an uncertain sort of resignation. As though he isn’t sure of what to believe, but unwilling to push it because he fears more conflict between them. It is a look Tobirama has become unfortunately familiar with.
He exhales slowly and purses his lips. He cannot tell Hashirama the whole truth without compromising his self-assigned mission, and his brother is ominously talented at sensing when Tobirama is being entirely dishonest. A half-truth then; something emotional but honest and believable enough that Hashirama will not dig further into it.
“You once said you wanted peace because of me,” Tobirama begins. “Because of our brothers. Because you did not want to lose us.”
“Yes,” Hashirama confirms readily.
“I… do not wish to lose you either,” he says, unable to help the awkwardness that settles over him. He avoids the softness of his brother’s gaze and shoulders on, eager to get this over with. “This conflict already cost us our brothers, father and my mother.”
Hashirama’s hand is warm where it comes to rest on his shoulder. “You need not worry for me, Tobirama. I am strong.”
“There is more than one way to lose someone to war, anija.”
That much is true anyways. Tobirama had indeed feared that being forced to keep fighting against Uchiha Madara would sooner or later cause him to lose Hashirama to the plagues of remorse and distress. It happens more often than anyone likes to admit in shinobi circles after all, and Hashirama has always been more susceptible to ails of the heart rather than the body.
His older brother knows this too because he only grimaces with something akin to guilt now as he looks at Tobirama. “I never knew,” he whispers.
Tobirama shrugs, uncomfortable by the intensity of this moment even though he curated it. “Make no mistake, I have no lost love for the Uchiha,” he warns. Not at this time anyway. “I just…would rather choose you.”
And that much is true. Through space and time, age and distance, Tobirama would always rather choose him.
The sentiment is not so unconditional for Hashirama, he knows. His brother is far too much of a visionary and quintessentially Senju in how his foremost loyalty is to his ideals. Tobirama doesn’t blame him for this. He was raised to lead and shoulder the lives of hundreds of people, and Tobirama was raised to act as his shadow. Fundamentally, they have been wired for very differently things.
Hashirama has always uniquely represented Tobirama’s past, present and future. That is not something that can be changed. It is a helpless, blameless fact of life.
As though he can see the thoughts in Tobirama’s head, Hashirama’s face goes slack in an expression of awe that makes him look stupid as far as Tobirama is concerned. “Is that what peace means to you then?” he prods.
Tobirama scoffs and steps away from him, rounding the table and pointedly looking to the map. “You’re getting ahead of yourself now,” he states flatly.
Sulking, his illustrious clan head all but whines, “We were having such a nice bonding moment though. I feel like I was really getting to see you in a whole new light, Tora!”
“Well moment over!” Tobirama snaps back, decidedly having reached his limit for sentimentality for the rest of the year.
Shoulders drooping, Hashirama pouts. “You so rarely say nice things to me.”
“You should have savoured it,” Tobirama counters sarcastically. “Now, focus on the problem at hand. What do we mean by a long-term defensive measure?”
“Barrier seals?” Elder Ayano blinks. “Aren’t those very draining of chakra? How will you keep these powered consistently as you propose to?”
“By repurposing the principles of senjutsu to apply them to fuuinjutsu,” Tobirama explains. “The seals will remain permanently fuelled by natural energy rather than the chakra from a human source.”
The bewildered looks on the faces of the council members remain fixed. Elder Hanabi asks in half-disbelief, “Is something like that even possible?”
Hashirama beams as if he has been waiting all along for someone to ask. Knowing him, he probably has. Proudly, he declares, “Tobirama figured it out.”
He technically stole the idea from the future where he and Mito developed the seal together as a defence mechanism for Konoha, but needs must. The original seal had itself been a redesign of Uzushio’s famous barrier which powers itself using the natural underwater ley line of chakra that the island is built on top of. Konoha’s location had no such thing, so they had had to essentially manufacture an artificial ley line using a seal that would passively siphon chakra over time and could be used to power a temporary barrier over the entire village when activated by the Hokage.
Using senjutsu as a foundation, although extremely difficult because of the complicated process of harnessing the natural energy of the environment, is more conducive to regular usage of the seal to be a more active part of their defence.
“Anija helped,” Tobirama says when the attention of the room turns to him after Hashirama’s proclamation.
“I—I’m afraid I don’t understand,” Elder Watari admits. “Senjutsu is a scared art for a reason and the process of learning it is—”
“I didn’t learn senjutsu,” Tobirama corrects mildly. That would be an infringement of Hashirama’s contract with the toads and a violation of the treaty between Mount Myoboku and Ryuchi Cave. It simply isn't his place since he never had a contract with either. “Does everyone understand what natural chakra is as opposed to life chakra?”
“Life chakra is the energy that binds the soul to the physical vessel, and natural chakra is what binds the vessel to the universe at large,” Head Medic Saionji states, eyes sharp with interest.
Hashirama inclines his head. “More specifically, natural chakra is actually the energy emitted by the vibrations of the atoms of living things. It is usually far too little to really be measured quantifiably. Senjutsu is simply a channel to harness this energy from the world around you because it cannot be drained so long as organic matter continues to exist. Put simply, you must become aware of the rate at which your own atoms vibrate and then match the energy emitted by your life chakra to that of your natural chakra, thus creating a compatible path for the natural chakra of your surroundings.”
The explanation is obviously lost on most of the room who have never had to educate themselves on this level of chakra theory. Tobirama doesn’t understand why these people insist on asking questions when they’re incapable of understanding the answers. It’s a waste of everyone’s time really.
He sighs. “The basic underlying principle is resonance of natural and life chakra.” That receives a few slow nods at least. “Using anija’s mokuton as a basis, I created a mathematical model to determine the average frequency of the chakra generated by the woods at large and that will function as a source for the barrier.”
“We can ward off some sections of the woods and reroute our patrols everywhere else. We’ll cover ground more efficiently this way and save manpower while we’re at it,” Hashirama says.
Elder Kaname considers this. “We will have to rework the paths leading to the compound and teach them to everyone.”
Tobirama hums. “It would be possible to anchor the seal with blood to allow our kin entry unhindered.”
“And those who are brought into the clan through marriage or adoption?” Hashirama asks, brows furrowing.
“They will have to be keyed in individually.”
“A bit tedious,” Elder Hanabi notes. Her mouth twitches into a smile. “Ultimately, however, it seems like it would be worth it.”
Ryouhei—the head of their intelligence division—asks, “Have you finished running trials for the seal?”
Nodding, Tobirama informs, “The trials were successful, but my current formula needs to be modified slightly to not harm the source since we are looking at long-term usage.”
“And how soon could something like this be implemented?” Elder Takao asks, pushing up his glasses slightly.
“That depends,” Hashirama cuts in before Tobirama can respond. “Is everyone willing to see this proposal to implementation?”
The answer is, of course, unanimously in favour for it. They had known that it would be.
“We can start setting up within the fortnight.”