Chapter Text
Your name is Mary Kingston, and you are fourteen years old. You like hanging out with your few friends, reading books and watching anime. If you'd survived to various points of young adulthood, you'd have shaken your head in dismay at your 'shit taste', so to speak. You instinctively trust authority; you run to teachers and parents. You'd like to think you're pretty smart, and you are - even got skipped ahead a grade - and you mayyyyybe have a crush on your best friend.
You have also been hit by a truck at high speed, and can see your legs all the way on the other side of the road; so none of that will be of particular relevance to you any longer. Except for that bit about shit taste in anime, we're getting to that part later. Being bisected by a truck is understandably very painful, and you are currently making incoherent but pained-sounding noises as you die horribly. It wasn't as if you'd done anything to deserve it - the worst thing you'd ever done was be mean to that one girl, and she'd started it.
Whether by overzealous karmic retribution or simply bad luck, you breathe your last breath, and the world fades away.
Mary woke up, which was surprising in and of itself. She didn't find herself staring up at a hospital ceiling, nor in an ambulance at the scene of the accident. Instead, she found herself staring at the most high-definition dirt she's ever seen. It reminded her of the first time switching from a DVD to a Blu-ray as a little kid. She could make out details that she'd never even known were missing. She looked up and saw a blur of dark clothing and red eyes vanish into the night.
Around then, she noticed the bodies. Not just a couple of bodies, but dozens and dozens killed in every manner imaginable. A few looked like they'd been able to put up a fight, but most of them seemed to have died running. Mary panicked - she knew intellectually that these kinds of things happened, but to her, they'd been constrained to the pages of a history textbook or a news report. They didn't happen here.
She scrambled backwards on too-powerful limbs, kicking up dirt. She was at once utterly unfamiliar and familiar with her own body, a stranger and herself. Fire burned in the distance, and she could smell something she told herself was cooking meat because that meant that it wasn't the smell of burning corpses. Because people aren't meat, aren't left to burn where they fell.
Her limbs suddenly started to burn, and then her chest and then everywhere. It felt like someone replaced her blood with fire, and she couldn't speak because she was too busy screaming. Her eyes felt like they were going to melt, and her limbs were a confusing mess of phantom images. She saw what would be over what is, and nothing made sense anymore.
Her eyes receded back to their new natural black, the spinning red and black pinwheel fading. The world made sense again, if only for a moment. Mary breathed in, trying to calm herself. She had to get out of here before whoever did this returned.
Hisana sat up in her hospital bed, determined to get on with the difficult task of figuring out exactly who she was. Well, not in the sense of her goals in life. She began the rather simpler task of finding out the simple facts of family and status. Because if she really was a Sasuke replacement, things were going to get more than a little insane. Things had basically turned out all right in the end in the manga, but there were an awful lot of coincidences that led to that exact outcome. Even if she was barely related to Sasuke at all, the fact that there were two Uchiha running around Konoha was bound to change something.
She'd always, in her previous life, found the other parts of the manga than the Uchiha metaplot more interesting; a fact she was silently cursing now. Though cut down in the zenith of her fandom as she was, she was sure she could remember enough. She tried to cast her mind back, but she wasn't really sure what she was supposed to be doing.
Then, of course, it hit her all at once, or at least seemed to. She had vague memories of her mother and their small house at the edge of the compound. She remembered a childhood defined by loneliness and exclusion. She remembered the shame she'd eventually figured out she'd caused her mother. A bastard child tainted with commoner blood; with a lineage so weak she was never expected to awaken a Sharingan at all. Let alone at eight years of age. She isn't even technically a Uchiha. On her birth certificate, it merely read "Hisana".
Now, she might very well be all that's left of them to the Leaf. There's a cruel irony in that, and perhaps an explanation for her survival of the massacre. Though surely there must have been some other reason she was spared. She can't have been the only child from a weak line with an embarrassing parent. Hisana was startled by a knock on the door, followed by a uniformed medic making her way into the room. The medic was a tall woman with an ugly burn scar across much of her face.
"Ah, you're awake, Miss Uchiha. There are quite a few people who want to speak to you, if you feel you're up to it," the medic said, reading the output of a quietly beeping machine and checking it against a chart at the foot of Hisana's hospital bed. The lack of bedside manner didn't particularly bother Hisana, but it did seem odd.
"W-water, please," Hisana croaked out, finding her voice unfamiliar and her throat parched. The medic procured a glass from somewhere, helped Hisana sit up and handed it to her. The water inside it tasted odd, but not awful. "Did anyone else... survive?" Hisana asked, and there the memories were still fresh.
"I'm afraid only Sasuke, of the main line, survived, and he's in a genjutsu-induced coma. None of the non-clan caretakers or merchants were killed, either."
Hisana just nodded her thanks. So she wasn't a replacement for Sasuke, but she was still close enough to the main plot to inevitably drag her into it. That simply came with being a Uchiha in this age.
"I'll tell the Hokage you're ready for him, thens" the medic said, and again, Hisana was slightly perturbed at her bedside manner. Not that she minded, exactly, but the nurse wasn't doing a very good job at caring for the traumatised eight-year-old she ostensibly was.
The Third Hokage, the so-called 'God of Shinobi', was certainly aware of what had happened to the Uchiha. Though the massacre may have been ordered by Danzou, Sarutobi seemed like the kind of man who'd blame himself for it; citing his failure to negotiate a peaceful solution to the ongoing crisis and the fact that he was the ultimate authority for all Konoha shinobi. She wondered what he'd want to talk to her about - it wasn't like he needed answers on what had happened.
He entered the small hospital room, and Hisana's first impression of him was that he was old. Weary and broken down; rusted and abandoned - those were the words she'd have used to describe the God of Shinobi. Without any prior knowledge of him, she'd be hard pressed to see him fighting off an aggressive house cat; let alone dozens of superpowered ninjas. Of course, then she felt that 'heat' again, and she understood his reputation just fine. The medic that had first checked on her was the largest chakra signature she'd sensed yet - but Sarutobi was something else. Even tightly constrained as it must be, it was like standing next to a raging bonfire.
Hisana shuddered at what the true masters of brute force amongst ninja must feel like if Sarutobi, a man past his prime and never famed for his brute power, was like this!
"Hello, Hisana," he said quietly, sitting down on a slim wooden chair next to her bed.
"Lord Hokage," she intoned, bowing her head as much as she could.
"Please, dear, there's no need for such ceremony here. You've suffered enough that I won't inflict any more torture upon you." He said, and Hisana couldn't help but laugh. "I'd have preferred to wait until you were recovered to do this, but responsibility waits for neither reason nor mercy. Normally, your... cousin Sasuke would have to deal with this, but he is currently in a coma that seems beyond our medic-nin. You, as the last remaining and mentally capable Uchiha, are now acting clan head," Sarutobi said, then paused. Hisana felt confused for a moment, but then remembered the comment about all the various non-Uchiha who lived in the compound, and of course, the land itself must be astronomically valuable.
She was at best fourteen! How did anyone expect her to deal with something like that? It was just absurd. She remembered that Itachi had been thirteen when he'd killed her (how quickly her thoughts changed) clan. He'd been younger than that when they'd given him a position of authority within the village's military. She was going to have to get used to a whole different concept of age in this screwed-up world where six-year-olds could wield military authority over grown men.
"I see. What do I have to... what do I need to do?" she eventually replied.
"Without your mother to teach you, you'll need to enter the academy. I know that the clan kept you home before, but well-" Sarutobi began, but Hisana interrupted him.
"They're not around for me to embarrass anymore?" she asked and felt tears welling in her eyes at the mention of her mother in this world. Why, she thought, would she cry over something like that? She didn't know the woman, didn't have any fond memories of her.
Only she did, and they were terrifyingly real. That was the moment she realised she was neither Mary nor Hisana entirely, that she hadn't just taken over some poor girl's body wholesale. Sarutobi put his hand on her shoulder.
"I knew your mother, distantly. She was an exemplary ninja and a better mother. She gave your clan nothing to be ashamed of, and neither did you. And I think we both know that you have proved yourself a true Uchiha in the only way that matters to a ninja. The compound will take some time to be habitable again, and a funeral for the lost will take some time to arrange. In the meantime, you will have an apartment under ANBU guard provided to you. If you have need of anything, or even just need someone to talk to, my office will be open to you. It will surely be an improvement over the incessant natter visits from other clan heads are filled with," Sarutobi said, as Hisana blinked back tears.
"Thanks." She said, barely managing to get it out. Sarutobi nodded and left. Hisana was alone in an almost featureless hospital room, left alone to contemplate her future.
She managed to steady herself, keeping her hands from itching at her skin. She no longer felt such terrible, constant pain - but she felt something moving beneath her skin, and it disturbed her. She could feel it in the air, too, or something like it. The stuff in the air was cold and dead, ash to the fire that burned inside her.
Mary tried to stand and merely stumbled for all the good it did, but Hisana didn't stumble, and so the girl who was both Hisana and Mary managed to get to her feet after all. She saw the bodies that were at once her friends and family; then, at the same time, strangers who had barely been ink on paper. Then, almost all at once, she felt the fire fade. Her vision became a mess of grey blurs, and she fell.
Hisana awoke in a hospital bed. Then she recoiled at what she'd just thought. Wasn't she Mary, and this girl whose body she'd hijacked Hisana? Only, no, that wasn't quite right. She could quite clearly remember her boring, everyday life and Hisana's early life. In her memories, it was idyllic, though with her new perspective, it was also mildly terrifying. The window opened up onto an iconic, if fictional, cityscape. If she held any doubts as to her location, the four faces carved into the mountain quashed them. She had somehow awoken in the body of a female Uchiha in the last moments of the massacre, placing her squarely in the middle of the plot of Naruto.
Which was bad, because Mary was about as qualified to be a badass ninja as she was any other kind of badass - not at all. She could only hope that she hadn't replaced Sasuke, but her memories of before the massacre were still hazy.
But if Mary couldn't do what she needed to do, then perhaps Hisana could. She could still feel the vaguely prickling heat within her that she now knew was chakra, and she could feel that same heat emanating from various directions - was that other people's chakra? If it was, she couldn't see how anyone in the series got useful information out of it, and Hisana's scattered memories proved useless there. She hadn't been taught anything about it, and she didn't seem quite nearly so sensitive to it prior to their... merging.
Hisana remembered one more thing about arriving here. Using something she'd long been taught, but never expected to need, she channelled power to her eyes. The world gained a slight red tinge, and she saw fire. It was stunningly natural a thing to do, somehow. She saw the flow of power through walls, the vast sea of quiet puddles and raging oceans in the village below, and she saw her own movements before they happened. In the hand mirror on her bedside table, she saw her single tomoe spinning against a red glow.