Curse These Old Bones - SI as Hiruzen Sarutobi in Naruto

Chapter 5​

Week 1 after reincarnation, four weeks before canon.

Konoha Academy

"Troublesome," Shikamaru muttered under his breath, his voice just loud enough to catch a few ears but too soft for Instructor Mizuki to hear over the lesson.

"Hey, you woke up?" came Naruto's excited whisper from the next row, leaning precariously over his desk to peer at him.

Shikamaru didn't bother responding, deliberately staring straight ahead with the glazed expression he had mastered over years of perfecting the art of ignoring Naruto. Maybe, just maybe, if he didn't react, Naruto would give up and stop pestering him.

He slouched further into his seat, propping his chin on his hand. Normally, he'd have dozed off by now, letting Mizuki's droning voice serve as background noise. But today, something was gnawing at him—a sense of unease that refused to be ignored.

It had started yesterday, when his father, Shikaku, had called him into his study. It wasn't the usual "how are your grades" talk, nor the occasional lecture about putting in more effort. Only his mother did those. Instead, his father had asked him a barrage of questions about the Academy—details about the instructors, the curriculum, and even the students. Shikaku had sighed a lot during that conversation, his sharp eyes narrowing at Shikamaru's answers in a way that left the boy unsettled.

And now, there was this... anomaly. One of the other students—a boy whose name Shikamaru didn't even bother remembering—had been glaring at Mizuki with a level of hatred that was unnerving. It wasn't the usual frustration of a kid stuck in a boring lesson. No, this was something deeper, darker, the kind of intense loathing that made Shikamaru's instincts twitch. No normal kid stared at an instructor like that.

"Troublesome," he muttered again, tapping his pencil lightly against his desk.

Maybe he should tell one of the teachers about the weird kid. But then again, if his father had been asking about the Academy, and sighing the way he always did when he was stuck dealing with something annoying, it probably meant the adults already knew something was up.

Still, it wouldn't hurt to mention it tonight, just in case. He could already hear Shikaku's exasperated response, something about how troublesome his son was for getting involved at all. But that was fine. His father would listen.

For now, Shikamaru closed his eyes, leaning back just enough to feign indifference while keeping one ear tuned to the odd tension in the room. Whatever was happening, it was bound to be more effort than he wanted to deal with.

Hokage Tower, Underground Laboratory.

Kanna Sarutobi's eyes burned with exhaustion as she surveyed the bustling lab beneath the Hokage Tower. Her dark hair, usually neatly styled, hung loose and disheveled around her face. A hastily tied ponytail did little to contain the strands escaping in every direction. She tugged at the collar of her oversized blouse, its buttons slightly misaligned in her haste that morning. The sleeves of her baggy pants were rolled up, revealing toned arms and legs honed from her earlier years of fieldwork—a stark contrast to her otherwise unkempt appearance. Despite it all, she carried an effortless allure, her sharp green eyes commanding attention as she directed the replenishment effort.

"Be careful with that crate," she snapped, gesturing toward an ANBU operative struggling with a box of delicate glass equipment. "That's not something you want to shatter." The masked operative gave a quick nod and adjusted his grip.

Beside her, another ANBU—wearing the mask of a cat, one she identified as a commander—supervised the whole scenery. Kanna crossed her arms, her blouse pulling slightly against her frame as she moved through the lab. The room felt alive again after years of disuse, but the sight of ANBU doing menial tasks still struck her as absurd. "Directing ANBU to organize a lab," she muttered under her breath. "Of all the ridiculous things."

Behind her and standing next to Cat, stood a woman in a generic, formless mask. She spoke up in a low, pointed tone, correcting another Anbu. "That's the wrong drawer for the stabilizers. Those belong in the temperature-controlled unit."

Kanna turned at the comment, her sharp gaze narrowing at the woman in the mask. "You know your chemicals," she said, her voice edged with curiosity. "Medicinal training?"

The masked woman paused for a fraction of a second before replying evenly, "Something like that."

Kanna filed the observation away. Interesting. But then again, this was a ninja village. Secrecy was the air they all breathed.

Kanna couldn't help but reflect on the sudden, drastic change in their father's behavior. It was jarring. As a former chunin who had left the active ranks years ago to focus on her medical career, she understood all too well the layers of secrecy that came with living in a shinobi village. Even in her role as the head of Konoha's hospital—a position of considerable importance—she knew there were truths she was never meant to uncover.

Just yesterday, their father had promised Hiroto that today he would share with him the same secret he had revealed to Asuma that morning. Whatever it was, it had clearly shaken Asuma, though he'd kept quiet about the details.

And now, as if summoned by her thoughts, they appeared. Her father entered the lab first, his movements measured yet purposeful. Hiroto followed close behind, his normally impassive face shadowed by a weariness that Kanna had never seen before. He looked older—ten years older, at least—as though the weight of whatever he had just learned had carved new lines into his features.

Kanna frowned, her sharp mind racing to piece things together. Whatever secret their father had shared, it was no small matter. Part of her was almost grateful not to be involved. If Hiruzen's newfound energy led him to pursue more knowledge and organize more family dinners, she could hardly complain. Small victories.

"Hah, Kanna," Hiruzen greeted her warmly as he stepped into the bustling lab. His tone was lighter than she expected, fatherly and familiar, a stark contrast to the tension emanating from Hiroto. Behind them, the last of the ANBU operatives finished replenishing the lab's shelves, their presence as silent as ever.

"Father," Kanna replied, her tone even but laced with curiosity. Her gaze shifted to Hiroto, whose jaw was tight, his eyes distant. But before she could ask anything further, her attention snagged on something behind them—a series of diagrams scrawled across the blackboard.

She stepped closer, her sharp green eyes narrowing as she studied the intricate illustrations. Among them was a detailed sketch of a cell, its organelles meticulously labeled. In the center, a spiral structure marked "DNA" caught her attention, but it was the accompanying notes about "mitochondria" that made her pause.

"Huh?" she muttered, her brows knitting together. "What's this?"

Hiruzen chuckled softly, his voice warm and teasing. "Still as curious as ever, Kanna."

She straightened, a faint blush coloring her cheeks. "I—well, of course I'm curious. This isn't something you see every day."

Hiruzen stepped closer to the blackboard, his expression softening into something almost scholarly. "Those, Kanna, are mitochondria," he said, gesturing to the detailed diagram. "Tiny structures within nearly every cell in the body. Their primary role is to generate energy in the form of a molecule called ATP—adenosine triphosphate. Think of ATP as the cell's fuel. The"-- her father stopped, and smiled as if he found something funny -- "Powerhouse of the cell."

Kanna tilted her head, studying the intricate labels. "So, they're like... tiny engines inside each cell?"

Hiruzen smiled, pleased with her understanding. "Precisely. They break down nutrients—glucose, fats, and other molecules—and, through a process called oxidative phosphorylation, convert them into energy. That energy powers every function in your body, from muscle contraction to neuron signaling."

She leaned in closer, her curiosity fully engaged. "And this happens in every cell?"

"Nearly every cell," Hiruzen corrected. "Red blood cells, for instance, don't have mitochondria. But in cells that require a lot of energy, like muscle cells, mitochondria are especially abundant."

"Fascinating… even Tsunade never mentioned this, at least not to my knowledge."

Hiruzen chuckled, his tone light but confident. "That's understandable. Tsunade is brilliant, but as my student, there are things I've learned she has yet to explore."

Then, he clapped his hands sharply, a decisive sound that cut through the atmosphere. Kanna immediately recognized the gesture for what it was: a dismissal.

"Well," she said, brushing a stray lock of hair from her face, "time to get to work."

She nodded respectfully toward her father and brother, her green eyes briefly flicking toward the woman in the nondescript mask, her curiosity piqued but unspoken. Then, with the fluidity of a seasoned professional, she turned and made her exit.

Understanding the dismissal, the ANBU operatives followed suit, filing out silently.When the last masked figure disappeared, only three people remained: Hiroto, still standing tall and stiff as ever, their father, and the masked woman.

Hiruzen made a subtle hand sign. The woman did not hesitate before reaching up and removing her mask. Her features were sharp, her light brown hair slightly disheveled beneath her coif. The strange black cracks that marred her face like fractures of obsidian caught Hiroto's attention immediately.

"This is Nonō Yakushi," Hiruzen said, his tone calm and measured. "A loyal operative. She's assisting me in some… very specific work."

He gave a curt nod, acknowledging her presence without comment. It was not his place to ask.

The silence hung for a moment, stretching like taut string. Then Hiroto broke it, his voice clipped but respectful. "What's your next step, Father?"

Hiruzen didn't answer immediately. Instead, he walked toward the corner of the lab, his movements slow but deliberate. He stopped before a large safe embedded in the wall, its surface covered in intricate seals. With a flick of his wrist, he placed his hand on the center seal, letting his chakra flow into it. The safe emitted a faint click before its heavy door swung open. Inside, a series of vials glinted under the sterile lights, each carefully labeled. Hiruzen selected one, holding it up for a moment before turning toward Nonō. "You may begin the analysis. And do not lose any drop!"

Nonō stepped forward, her movements precise as she accepted the vial. Her fingers closed around it with the care of someone handling something far more dangerous than blood.

Hiroto, however, barely registered the exchange. His mind was still reeling from the events of the past twenty-four hours. The revelations had been seismic: the Genjutsu his father had been under for years, Danzo's treachery, the truth about Orochimaru's experiments, the fact that some of his own operatives were spies for Danzo — and the horrifying details behind the Uchiha massacre.

And yet, here his father was, moving forward with a clarity and determination that Hiroto hadn't seen in years. It was almost too much to process.

Finally, he spoke, his voice heavy with the weight of his thoughts. "So, what are we going to do now, Hokage-sama?"

Hiruzen tilted his head slightly, an enigmatic smile forming on his lips. "What do you think about your life as ANBU Commander, Hiroto?"

Hiroto blinked, caught entirely off guard by the abrupt shift. "I…," he began, but the words faltered. In truth, he had rarely thought about it in personal terms. He had only served, his life defined by duty and unwavering obedience. The question lingered uncomfortably, forcing him into unfamiliar introspection.

"You're 38," Hiruzen continued, his tone uncharacteristically conversational. "You have a wife and a son you barely see. I'm the Hokage, and yet I spend more time with Konohamaru than you do. And I probably spent less time with him than I should."

Hiroto stiffened, his jaw tightening. "Are you…" he began, trailing off, unsure how to even articulate the shock and confusion swirling in his chest. Was his father suggesting he retire? Now, in the midst of a crisis of this magnitude? The thought was absurd, yet it hit a nerve Hiroto had buried deep. It was true—he had considered stepping down more than once, but guilt and the weight of responsibility had always stopped him. To hear his father voice it now felt surreal.

"We're in the middle of—"

"I know exactly where we are," Hiruzen interrupted, his voice calm but firm. "And I know what we're facing. But there is more than one battlefield, Hiroto. Danzo's strength isn't just in military power—it's political. And for far too long, the Sarutobi seat on the Clan Council has been empty. You should think about that."

Hokage Tower, Underground Laboratory.

Yamato followed Captain Cat into the Hokage's laboratory, keeping his pace measured as they descended into the sterile coldness of the room. The scent of disinfectant hung in the air, sharp and invasive. It wasn't the tools or the harsh lighting that set him on edge—it was the cells. Barely visible in the corners, the faint sound of restrained breathing echoed from them. He kept his mask firmly in place, as much for the sake of his expression as for protocol. Laboratories weren't unfamiliar to him. They weren't unfamiliar to Tenzo. And that was precisely the problem. But this one was the Hokage's - the man he trusted and respected the most. The man who had given him a chance to be someone he could be proud of.

The Hokage stood near the far end of the room, beside a woman in black robes. Her face was cracked with jagged black lines that seemed to hum faintly with power, as though the chakra within them couldn't be contained. A nun? Yamato's eyes lingered for a moment before he turned back to Captain Cat, who was lowering their target—a sedated boy wrapped in monk robes—onto the floor.

Yamato sighed internally, trying not to let his gaze follow the sway of Cat's hips as she moved. He scowled behind his mask, more at himself than anything. Professionalism, Tenzo. But it wasn't his fault she carried herself with such infuriating precision — and such a nice ass.

The boy's body hit the floor with a soft thud. He looked harmless enough, face slack, head shaved, robes wrinkled from their handling. But Yamato knew better than to take things at face value. He shifted uncomfortably, the questions from the mission still rattling in his head. Why a monk? Why such heavy sedation? And why Captain, the one who had been personally briefed by the Hokage, had told them to treat him like a Jinchuriki? He was sure the boy wasn't a Jinchuriki - every ANBU operative knew the names and identities of the nine Jinchuriki by heart.

Yamato's curiosity prickled at him, though he kept his posture neutral. The Hokage's gaze drifted toward him, and a faint smile tugged at the old man's lips.

"You're wondering why this boy is so important," Hiruzen said, his tone inviting rather than accusatory. Yamato smiled - his Kage knew him well, to analyse his thought even when masked - and hesitated. "The instructions were unusual, sir," he admitted. "We were told to treat him as if he were a Jinchuriki, but that doesn't align with our knowledge."

The Hokage nodded, his expression thoughtful. He gestured toward Sora, who remained motionless on the floor.

"This boy, Sora, carries remnants of the Nine-Tails' chakra," Hiruzen explained. "After the Nine-Tails attacked the village, fragments of its power lingered. A rogue ninja named Kazuma, once one of the Twelve Guardian Ninja, sought to collect and weaponize that energy. He infused it into his son."

Yamato's hands tightened at his sides, his thoughts immediately turning to the dangers of unstable chakra. No wonder they would have needed his Wood Release for containment if they did not manage to sedate him before he woke up.

The Hokage's tone remained calm, almost conversational, as he gestured toward the clay pot sitting on a pedestal near the corner of the room. Intricate seals coiled across its surface, glowing faintly as though waiting for a command.

"So, we're going to extract the chakra from Sora's body," he said with the same ease one might announce plans to brew tea, "and seal it into that."

Tenzo stiffened slightly, the words sinking in like cold water. "But… won't that kill him?" he asked. It wasn't a protest, exactly—he'd killed plenty in the name of the village. But he was a bit curious.

Cat, standing just ahead of him, turned her head sharply, her irritation practically audible even without words. Yamato didn't have to see her expression to feel her disapproval. She hated when ANBU operatives questioned the Hokage.

"It's fine, Cat," Hiruzen said, waving her off with a small, patient smile. "This is a good learning opportunity."

Yamato blinked behind his mask. A learning opportunity? For what?

The Hokage turned his attention back to the clay pot. "It's a fair question," he said. "Extracting chakra from a true Jinchuriki would kill them, yes. But in this case, the quantity of chakra in Sora's body—while significant—is a mere fraction of what resides in a true host. And with Nono here—" he gestured toward the nun with cracks running across her face, who stood like a silent statue—"he will survive. Probably."

Very probably? Yamato wasn't sure if that was supposed to be reassuring.

"You'll stay here," Hiruzen continued, fixing Yamato with a pointed look. "In case things get… messy. Be ready to use your Wood Release."

Yamato's eyebrows shot up under his mask. "Wait. We're unsealing a proto-bijū… right now? Here?"

Hiruzen's smile shifted slightly, becoming sharper, more amused. "What? Are you afraid, Tenzo? You can leave, if you want - even if the seals were going to fail, I could easily take care of it.".

He was going to say yes—because any sane ninja would be—but before the words could leave his mouth, Cat stepped on his foot. Hard. He bit back a yelp, gritting his teeth as pain shot up his leg. Had she used chakra in that stomp? He wouldn't put it past her.

"Whatever," the Hokage said, turning back to the seals without missing a beat. "Edo Tensei is taxing. Maintaining Nono here alone consumes nearly twenty percent of my chakra. If I want to summon additional support or create more durable blood clones, I need a battery. This chakra will do nicely."

Yamato's head was spinning. Blood clones? Chakra batteries? The Hokage was operating on a plane so far above the ordinary that it was making him dizzy. But before he could ask for clarification, Hiruzen clapped his hands, and the seals on the pot flared to life.

"Don't worry," Hiruzen said, his voice brimming with calm confidence. "This lab is sealed. Not a whiff of the Nine-Tails' chakra will get out. And if the proto-bijū, as you called it, puts up a fight…" He glanced back with a grin sharp enough to cut steel. "Well, I'll take care of it. It's nothing dangerous."

For a moment, Yamato simply stared, struck by the sheer audacity of the man.

Hiruzen stepped forward, his hands moving with the fluid precision of someone who'd been mastering seals longer than most shinobi had been alive. The pot glowed brighter as the script spiraled outward, forming a network of light that wrapped around Sora's prone body.

The first threads of chakra slithered out of Sora's body, red and viscous, writhing like sentient tendrils. It wasn't just energy—it was alive, aware, and malevolent. The air thickened with its emergence, growing so oppressive that Yamato felt it press into his lungs like an unseen hand clawing at his insides. The lights in the room flickered, their steady hum warping into an unsettling drone, and the very walls of the lab seemed to groan in protest.

The chakra coiled upward, a nightmare given form. It moved in unnatural, jerking motions, splitting and reforming into grotesque shapes—an ever-shifting cascade of claws, eyes, and fanged mouths that hissed and snapped at the air. A wet, guttural sound filled the room, somewhere between a growl and a scream, and Yamato realized it was coming from the chakra itself. The red haze carried an oily sheen, as though it were coated in some kind of infernal ichor, dripping onto the floor and sizzling as it burned invisible scars into the stone.

Sora's body convulsed violently, his back arching as if an invisible puppet master was yanking at his strings. His eyes snapped open, glowing with a sickly, incandescent red that burned with a hatred far older and deeper than the boy himself. Then he screamed—a sound so raw, so primal, it made Yamato's head pound and his vision blur.

The chakra poured out of him in chaotic waves, each burst a new horror. It clawed at the ceiling, painting it with shadows that danced like specters. The temperature in the room plunged, and yet Yamato felt sweat pouring down his back. The chakra wasn't just energy—it was a presence, a force that wanted to consume, to annihilate.

Nono stepped forward, unflinching, her hands aglow with green medical chakra. As she pressed her palms against Sora's heaving chest, one of the tendrils lashed out at her. The impact was instantaneous. Flesh sizzled away from her forearm, peeling back to reveal stark white bone, the chakra eating through her like acid. But she didn't even blink. Her focus was absolute, her movements mechanical, as though the agony didn't register.

Yamato stumbled back a half-step, his knees trembling under the crushing weight of the chakra's presence. His Wood Release pulsed at his fingertips, an instinctive reaction to the sheer madness unraveling in front of him. He could feel the chakra's intent—a rage so pure it defied comprehension, whispering promises of destruction in voices that weren't human.

Even Cat, usually as steady as a mountain, shifted, her hand falling to the hilt of her blade. It wasn't fear—Cat didn't scare easily—but the raw, predatory instinct to defend herself had kicked in. She'd stepped back, unconsciously, as though retreating from the edge of a cliff that threatened to pull her into a void.

And yet, Hiruzen Sarutobi stood firm in the eye of the storm, unbothered by the nightmare unfurling around him. His hands moved in perfect rhythm, forming seals with a precision that seemed to mock the chaos surrounding him. The chakra lashed out at him, a clawed appendage roaring toward his face, but he swatted it aside with a flicker of his own chakra like it was nothing more than an annoying fly.

"Almost there," he said, his voice calm, almost bored, as if this was another day at the office.

The seals he wove wrapped themselves around the writhing mass of red energy, tightening with every motion. The chakra screamed, its many mouths opening wide in a futile attempt to resist, but Hiruzen was unrelenting. He didn't rush. He didn't flinch. He moved with the quiet confidence of a man who had seen far worse and survived.

Finally, with a deafening crack, the last tendrils of chakra snapped free from Sora's body, spiraling violently into the clay pot. The seals on its surface flared white-hot before settling back into a faint glow, locking the monstrous energy away.

The oppressive weight in the room vanished instantly. Yamato staggered forward, gasping for air as his knees threatened to give out entirely. His chest heaved, his body trembling from the effort of simply enduring the ordeal. Even Cat exhaled audibly, her hand slowly dropping from her blade.

"Done," Hiruzen said, his tone as casual as if he'd just finished sweeping the porch. He turned to Yamato and Cat, his smile easy, his posture relaxed. "See? Nothing to worry about."

Yamato stared at him, his mind struggling to reconcile the calm, smiling man before him with the sheer horror they'd just survived. The Hokage had faced an eldritch monstrosity without so much as breaking a sweat.

Incredible, Yamato thought. He was truly the God of Shinobi.

"Now," Hiruzen said, his voice casual as if the room hadn't just been the epicenter of an eldritch nightmare. He glanced at Sora, who was now snoring loudly despite the faint scorch marks still clinging to his robes. "Go put him back in his room at the Temple of Fire. Make sure you're not spotted—Chiriku won't be pleased to find out we borrowed him."

"Yes, Hokage-sama," Yamato said, his voice steady despite the tremor still coursing through his body. He stepped forward, already thinking through the logistics of transporting the boy without drawing attention. He bent to lift Sora, but Hiruzen's voice stopped him in his tracks.

"Oh, and Yamato," the Hokage said, his eyes glinting with a mischievous amusement, "since it seems you're not particularly fond of dangerous missions, I have something more your speed. Once you're done, use your Wood Release to build me an amphitheater. I need it ready in a few days."

Yamato protested, his shoulders tightening. "Hokage-sama, I'm ready for dangerous missions," he said, trying to keep the edge out of his voice.

"Ah, excellent," Hiruzen said, smiling wider. "Then, you won't mind being part of the team that will have to track and kill mission to track and eliminate Hoshigaki Kisame? I should issue it in a few days."

"How big should the amphitheater be, sir?"