Work Header

Black Hole Heart

Chapter Text

Sakura’s mother gives birth at home, in the big bathtub off the master-bedroom, with just Sakura’s grandmother and one of her female cousins acting as nurse in attendance. The labour is long and gruelling and she strains and strains and eventually Sakura spills bloody and still – so frightfully still – into the warm water.

“No,” Mebuki says, then louder and furious, “No! You save her, right now!” She cradles her daughter’s head above water and holds tight enough to bruise if Sakura weren’t still and unbreathing, no pulse to speak of.

By all accounts, Sakura is dead for the first five minutes of her life. Then she bursts into movement with a huge inhale at the same time Mebuki sags unconscious. Sakura screams and writhes in the bloody water until her grandmother fishes her out and wraps her in a soft towel. “Hush now,” she says, “it’ll all be fine. Just breathe.”

Sakura’s green eyes flash and flick-flick-flicker the palest white before settling and she quiets. Her grandmother smiles and brings her out to show Kizashi his lovely new daughter.




She’s five and she listens to her friend Ino-chan from the park explaining what it means to be a kunoichi and protect the village. Inner Sakura – that rasping voice that’s been in her head as long as she can remember – stirs and perks up and listens. Sakura’s spine straightens and her eyes gleam and she commits every word to memory. Ino-chan’s kunoichi sound fierce and mighty and Sakura is only very small and the other children are cruel and make fun of her. Civilian children, she thinks with a vicious satisfaction that curls in her chest, would not dare.

When Sakura asks Mebuki that night if she can go to the Shinobi Academy instead, her voice comes out lower and her eyes look filmed over but it is still Sakura that asks. If Inner feels like she’s pushing forth then that’s just because they’re both excited.

Mebuki agrees immediately, though Kizashi cautions his daughter that they’ll still have to talk about it first. Inner curls content in her head and Sakura knows the way Inner knows that her mother will definitely let them do what they want.

They’re enrolled the next day and Mebuki looks strangely unbothered by her civilian daughter standing amidst the shinobi children who already know how to strike to hurt and handle weapons.




She’s eight and she falls down a steep hill on the cliff they’re hiking for one of their overnight survival excursions. Iruka-sensei doesn’t notice at first until Ino-chan’s shriek of alarm draws his attention to the tumbling pink-haired child. The rocks are sharp and there are sticks and dirt and even old weapons (these are shinobi excursions and even Academy students aren’t immune to the childish inability to lose a few things accidentally).

Sakura skids to a stop and feels her arm crack! It hurts – a sharp pain that radiates impossible heat – and when she looks down she can see the white of her bone poking out amidst the bright red outpouring of blood. Inner hisses sympathy and then she reaches.

The worst of the cuts smooth over as if they never were. The bone snaps back into place and Sakura whines at the pain while Inner shushes her It’s fine don’t worry see? All better. The skin seals over and by the time Iruka-sensei reaches her, Inner is exhausted but all Sakura has left to show for the fall are some mild bruises and a couple scrapes that don’t even bleed, not really.

“You were very lucky, Sakura-chan,” sensei tells her as he inspects her carefully and helps her to her feet. “Watch your balance on these paths – a shinobi must never lose their footing or they could jeopardize the mission.”

Inner thinks uncharitably that she wouldn’t have lost their balance. Sakura ignores her and smiles tentatively at Iruka-sensei, flushed with embarrassment at the mistake, “Sorry sensei.”

“It’s fine Sakura-chan,” he says. “Everyone makes mistakes.”

The next time Sakura starts to lose her balance, Inner plants their feet and says Steady now, not so far back. Sakura adjusts her hold on the cliff wall they’re climbing so she’s further forward and when she lunges for the next handhold she makes it with ease. Inner preens proudly in the back of her mind and Sakura grins in exuberant satisfaction.




Sakura is eleven and Ino-chan says they can’t be friends anymore because she has to focus on being the perfect girl for Sasuke-kun. Sakura thinks that it’s a pretty stupid reason to stop being friends and then, angrily, that she doesn’t want to be Ino-pig’s friend anyway if she’s willing to just toss them aside like that. Inner growls and curls her hands into fists and paces angrily.

He’s not even interesting, Inner hisses and alternates glaring daggers at Ino-pig and staring intently at the back of Sasuke-kun’s head. Sakura lets her because she already knows this lesson so missing out on the lecture doesn’t really matter.

He’s the last one left of the Uchiha after the Massacre, Sakura reminds her. One of the founding clans of Konohagakure.

He’s a brat no matter how delicious his rage is, Inner retorts and settles into their limbs, stretching and indolent and angry. Always angry. Let’s give him something real to sulk about.

Sakura may not have a crush on Sasuke the way Ino-pig does, but she also doesn’t want to hurt him. Luckily, Sakura is still annoyed about Ino-pig abandoning them and she doesn’t mind taking out her anger on her.

When they have their taijutsu lesson, Sakura makes Ino-pig bleed and Iruka-sensei has to separate them. Ino-pig goes to the nurse to have her split lip seen to while Sakura is told to run laps for not stopping the spar when she was told to. Inner licks the blood and abrasions off their knuckles before anyone sees and purrs contentment. Sakura breathes through the ache in her lungs and feels nothing but vicious satisfaction.




Kakashi-sensei gives Team 7 – Sakura, Sasuke, and Naruto – a final test before they can be full genin. She watches Naruto and Sasuke charge their very famous jounin-sensei and prods at Inner in mingled horror and disbelief.

Inner grins sharply when both boys are deflected with ease. Morons, she says.

“We aren’t much better,” Sakura mutters out loud – too busy trying to keep track of both her wayward teammates and Kakashi-sensei to bother speaking in their head.

She can feel Inner roll her eyes and glares into the middle distance. “What?”

None of us are, she says and even though her voice is pointed Sakura can feel the ever-present anger crest at the admission. But genin teams are always three so…

Teamwork. Of course.

Kakashi-sensei drops a genjutsu on them while Sakura is searching for Sasuke. Ideally she convinces him to work with her first because Sasuke-kun will never agree to work with Naruto but she’s pretty sure she can get him to let Naruto help after the fact. It’s a subtle genjutsu – so light and careful she’s sure none of her teammates would notice. But Sakura has chakra control in the 90th percentile as a genin; to slip foreign chakra past her own takes a proper genjutsu master and Kakashi-sensei isn’t coming at them seriously.

Inner laughs hysterically at the image of Sasuke bleeding to death. Sakura kneels down and brushes a hand through the ‘blood’ with mild interest. Inner continues to laugh while Sakura sighs and mutters, “It doesn’t even have a smell.”

Good thing, Inner says and manages to get her giggling under control, or I couldn’t tell you he’s over there – fifty yards.

When they practically trip over Sasuke’s head where he’s buried up to his neck, even Sakura has to stifle laughter. “Oh, Sasuke-kun,” she says on a sigh and shoves the crying hysterics that is Inner’s laughter to the back of their mind to focus on the problem at hand.

They do manage to eventually work together but it isn’t until Inner grabs the other bento and offers it to Naruto that Kakashi-sensei pronounces their teamwork satisfactory and passes them. Sakura seethes, as if teamwork is our only problem, and Inner gets to be the calm one for once. She smiles at their new sensei with perhaps too many teeth with too many points but when he does a visible double-take Sakura is the one grinning instead.




Catching Tora the cat is easy when all Inner has to do is growl from where she curls in Sakura’s chest and throat and vocal cords. The cat freezes every time and if they get a whole bunch of side-eyes from the mission desk nin, well. That’s hardly her fault they fail at catching a cat, isn’t it?

Naruto tells Kakashi-sensei that Sakura has always been scary when she wants – he’s not surprised Tora is smart enough to stay put rather than face her wrath. Even Sasuke nods a little at that, taking the practically docile cat from Sakura’s arms when she makes a face at the cat hair all over her dress.

After the fifth time, Tora actually leaps into Madame Shijimi’s arms. Naruto complains and Team 7 gets their first C-rank mission.




Tazuna is drunk but he’s not a drunk. Inner inhales and rumbles, his liver is perfectly healthy. We should eat it for lying.

Sakura isn’t exactly opposed to the idea – but more so in the sense that she doesn’t like being lied to than the eating organs part. Let’s wait and see, she says. Inner sulks and curls and uncurls their fists, claws out and deadly, until Sakura catches Naruto looking sideways at her. She grins at him and he grins back.

“He’s not a real drunk,” Naruto whispers conspiratorially. “I know that.”

Naruto lives in the poor part of town so he would know and even Inner knows there’s something dangerous in his belly. They haven’t figured out what yet, but they both agree that if even Naruto knows something’s up that they need to be on their guard. “Teamwork, right?” she says and holds out a hand for a low-five.

Naruto laughs quietly and slaps his palm to hers, ignoring the dark claws still extended, and his grin is just a touch toothier than usual. “Teamwork,” he agrees firmly.

When the Demon Brothers come at them with the acrid stench of poison Inner!, she and Naruto tag-team while Sasuke keeps Tazuna back. Between the sudden uptick of fear and rage, and the wash of hot blood between their claws, Sakura feels Inner retreat with a hum of satisfaction and leaving her with a mouthful of throat from where they’d sunk in their teeth and ripped.

She has blood on her face and Sasuke looks mildly disgusted (though that may be more with the pool of vomit from Tazuna retching near his feet) but Naruto is quick to offer a cloth and his canteen. She swallows the flesh in her mouth and tries not to think about it. Kakashi hovers awkwardly nearby and she glances at him warily. “Sorry,” she says, “I just…” she trembles a little and Inner flutters anxiously even if she doesn’t feel an ounce of shame.

Kakashi softens and helps her clean up. “We’re shinobi,” he says quietly, reassuring, and Sakura remembers that his family was always associated with wolves, wasn’t it? “You’re not hurt? Then as long as you’re keeping yourself and your teammates safe, that’s all that matters.”

Inner smiles hesitantly, too many too sharp teeth, and says, “thank you, Kakashi-sensei.”

“Now,” he says louder, and turns a reprimanding stare at Naruto, “I know Sakura-chan caught on to the poison but what about you?”

Naruto squawks alarm and paws frantically for any cuts. Sasuke huffs a disbelieving sigh and shares an exasperated look with Sakura; she shrugs at him. Naruto went through their poison resistance regime same as Sakura – absolutely no reaction from even the highest doses when even kids like Ino-pig (with her family’s long history of poison masters and her minor dosing since she was a baby) were sick and miserable.

He might not have known that the poison resistance doses were anything but boosters, Inner offers. If I hadn’t told you I was filtering out our blood, you wouldn’t have noticed until we were puking.

The Academy primes all students to withstand most common poisons from the Land of Fire in a semester-long of increasing doses disguised as booster shots. Parents all sign consent forms and students come out with stronger immunities and a warning to never just trust someone giving you unknown substances.

They shuffle over to Sasuke’s side and wrinkle their nose at the smell of vomit. “Okay?” Sakura asks and nudges him carefully. This is perhaps the first time they’ve allowed themselves to just react in public like that.

“You’re the one who had all the fun,” he says finally. “Next time, you guard the client.”

Even if it galls her and makes Inner writhe and strain under her skin, Sakura honours his request and stays out of it when Zabuza attacks.




The kid – Inari – yells at Naruto about heroes and going to die and Inner cackles because all that fuss sounds like fun compared to sitting around and just waiting for thugs to beat them up.

Kakashi tries to divert the boys’ attention from that by teaching them how to climb trees. Inner, of course, doesn’t need chakra to climb so Sakura has to scold her away from helping. I can do this, she says and focuses on letting her chakra cling and seep into the bark the way Inner would.

It’s easy and she climbs to the first branch big enough to hold her weight just so she’s still in plain view to gloat over her teammates. Kakashi-sensei smiles at her from behind his mask and tells the boys they’ll just have to try harder to catch up. Then he takes her aside and says, “Now try that on water.”

It’s mildly more difficult but her control is perfect and she manages it after just a moment. Kakashi-sensei sighs a little and mumbles, “I was hoping that would be more difficult…”

“Don’t worry Kakashi-sensei,” she says soothingly. “It’s still a helpful skill – especially around a bridge.”

The worrisome gleam in his eye makes Inner stir.

In retrospect, she should have anticipated being relegated to guard duty.

Smug jounin, Inner grumbles from where she’s settled heavily in Sakura’s shoulders. Sakura looks down the length of the bridge shrouded in fog and listens to the uneasy muttering of the workers and the lapping of waves at the base and sighs.




So it turns out that the hunter-nin is actually a boy named Haku and Naruto – because of course he did – has befriended him in the meantime. They obey Kakashi-sensei when he says to guard Tazuna but the fog that spills unnaturally thick is aggravating and their eyes turn milky white as Inner lends her vision to peer through it all.

They watch Sasuke fall and watch the thing inside Naruto come roaring out of his chakra – red and furious – and then Tazuna is saying gently that they should go over. The gentleness throws her because…

He’s got a pulse still, right? I’m not imagining that? She peers down at Sasuke and nudges him with the toe of her sandal. “Wake up.” Tazuna seems to be trying to pull her away as if he’s dead and not just being lazy.

Like we’d leave that boy alive if he didn’t, Inner scoffs. The possessive black-hole of a heart they share has already swallowed Team 7 into its depths and neither of them are keen on letting anyone threaten what is theirs. Sakura thinks Tazuna is being dramatic when Sasuke coughs himself awake and flicks Naruto in the forehead for being worried for even a second.

“Hey!” the blonde says and swats at her hand. She reaches out and pinches unerringly at the soft side of his hip and he yelps.

“Of course he’s alive, idiot,” she says. “Like Sasuke-kun would just let himself get killed.” She holds out a hand to haul him up and gives him a stern look while Naruto is busy being offended in general. It was close and she does not approve.

He makes a soft noise of assent and assurance both and lets his hand linger in hers long enough to squeeze tightly before withdrawing and turning back to watch Kakashi square off against Zabuza. It’s not really a competition – Kakashi-sensei is definitely going to win. When lightning sparks and pools in his hand and a sound like the chirping of a thousand birds fills the air Sakura knows –

Inner hisses and writhes and screams agony and Sakura clutches at her chest and then her ears and wants to run but she can’t. Naruto makes an alarmed sound and draws her into his chest and she burrows in – feels Sasuke come up behind her and hears him asking harshly what the hell is wrong and Naruto snapping back that he doesn’t know – trying desperately to escape that noise.

Sasuke makes the connection first and the boys box her in until there’s a pained cry and the noise vanishes as if it never was. Sakura is dizzy with sensation, Inner a messy puddle and weighing down her every limb, but she turns to see the boy, Haku, slide off their sensei’s hand where it’s buried wrist-deep in his chest. She thinks Kakashi might look surprised or horrified but her eyes are bright green and she can’t make out the details.

When it turns out Gato was always planning to betray Zabuza and his apparently beloved apprentice, Inner finally stirs. He what, she says flatly. I had to hear that and it turns out they could have been on our side the entire time?

When Naruto and Kakashi form up a small army of clones, when Sasuke’s sharingan gleams crimson, and when Zabuza clenches a knife in his teeth and charges with a feral sort of snarl. Sakura takes one step, then another, then Inner creeps over her skin – inky black and streaked with white. Her jaws have too many teeth and open too wide and they don’t care. They almost died and this man, this scum, this prey, deserves nothing less than screaming death.

In the chaos no one really notices a small black and white blur tearing apart grown men with her bare hands and ripping out throats with her teeth. One poor soul actually loses his entire head to their rage and by the time Inari and the townsfolk show up to scare off the rest of them, Inner has settled heavy and full in the general vicinity of her stomach. Sakura’s free of blood this time, because Inner absorbed every drop, but she’s fiercely, avidly, and viciously satisfied at the carnage.

Zabuza sidles up to her and offers her a high-five. He kind of has to flop his arm about to do it and he collapses almost immediately after he manages a “Good job kid, maybe Konoha-nin aren’t so useless after all huh?”

She’s sad when he dies and insists that they leave his sword as a grave-marker even if protocol dictates they take it with them. Kakashi-sensei ruffles her hair affectionately and tells her it’s a kind gesture.

Naruto tells them in whispers about the Kyuubi sealed in his stomach; Sasuke admits he’s one of the last two people in the world with natural sharingan and that he wants to kill his brother for the slaughter of their family; Sakura and Inner say they’ve always been like this and that Sakura is pretty sure she wouldn’t have been had she not decided to be a kunoichi.

“We’re glad you did though, Sakura-chan,” Naruto whispers on her left as they huddle together by the fire and Kakashi keeps careful watch. “Wouldn’t be the same without you.”

“You know what rage feels like,” Sasuke says on her right. It isn’t a confession or an admission but Inner does know rage and she preens at the acceptance implied.

“We’re a team,” she says firmly. “We watch each other’s backs – no matter what.”