Naruto Uzumaki, Lord Seventh Hokage, had absolutely no reason to travel back in time. When he was younger and more naïve, he may have desired to undo some of the tragic losses in his life, but the man he was now knew that such things were an inevitable, even necessary part of his life.
He was much older and wiser than he had been during the Fourth Shinobi War. He knew better than to go fooling around with the laws of nature.
Theoretically, time travel was possible. Nothing in what shinobi knew of physics and the laws of causality directly contradicted this. There were even some who claimed it had been done before, who claimed to know of people who knew of scrolls which held such powerful and forbidden techniques, and while there was no definitive proof that any of these alleged time travel jutsu were authentic, scholars on such matters generally agreed that there was always a chance.
Which was why the Lord Seventh Hokage went to such lengths to seal away any and all such jutsu scrolls he came across. Whether they worked or not, it was Naruto's opinion that time travel was something far too dangerous to be risked.
He had no desire to find out if any of those so-called time travel jutsu actually worked. As far as he was concerned, the risks far, far, FAR outweighed any of the meager potential benefits.
The world was at peace. It wasn't a perfect utopia by any means, and there were still occasional, limited conflicts, but compared to the uneasy, watchful peace of his youth, and the all-out chaos of his teenage years, what the hidden villages had now was like a dream.
So much effort had been put into forging and upholding these truces, these good-will pacts of limited mutual disarmament and demilitarization, that Konoha's honorable Nanadaime saw the possibility of time travel as nothing but a headache just waiting to happen. The alliances, the promises, the slowly and painstakingly established friendships which had enabled all of this to be achieved were all just too valuable to be thrown away in a fit of piqué.
He was not about to let anyone stupidly undo all of the work he and the other kage had done, especially not anyone so full of themselves as to honestly think that they could do better. Nothing was perfect. What they had now was as close as Naruto believed they would ever achieve within his lifetime.
So he wasn't about to let anyone go and start fucking up everything he and his comrades had sacrificed so much to accomplish.
Naruto Uzumaki had no reason to go back in time. Some things may not have turned out how he would have wanted, but the risk of undoing all of the good was just too high, too appalling, to even consider.
Unfortunately for the Lord Seventh Hokage, however...
...the Powers That Be would apparently beg to differ.
When the thirty-five year old Naruto woke up in a filthy, dank apartment, his first instinct was to wonder if Kiba had dragged him off to some dump on a bender. His second instinct, upon getting out of bed only to stumble over his own feet and land flat on his face, was to wonder what the hell his drinks had been spiked with.
It wasn't until he stood and shook his head, looking around and narrowing his eyes, that he realized something was very amiss. The scale of this room was all off. It was far too big for an ordinary person.
He wasn't exactly the tallest guy around, but he wasn't a shrimp either. And Naruto hadn't been this close to being at eye level with a doorknob while standing straight up since...
...well, since he was just a kid.
"I swear, if this is Yamato's idea of a prank..." the Lord Seventh muttered, scowling and grumbling about wood style users with terrible senses of humor.
Standing back up, Naruto extended his chakra senses, expecting to find a telltale trace of the ANBU captain's pine-scented essence.
What he found instead left him extremely bemused.
He was SURROUNDED by unfamiliar chakra signatures. And while maybe only one or two of those signatures were actually within a dozen meters of him, it was still suspicious enough to make him frown.
Naruto crossed his arms, wondering absently why they felt... scrawnier than he remembered.
He was very proud of his sensory ninjutsu. Years of refining his technique with help from Karin-neechan had enabled him to wield considerable empathic powers even without tapping into Kurama's chakra. Even half asleep and possibly hungover, Naruto had a rough maximum sensory range of one hundred kilometers.
If he dipped into Kurama's chakra, his area of perception would easily encompass almost the entirety of the elemental nations. And while Naruto wasn't anywhere near obsessive enough to try and commit every one of those innumerable chakra signatures to memory (particularly since his ability to detect life was acute enough to even pick out individual microscopic organisms, if he focused), to feel only two or three immediately familiar auras within his entire base range of perception was distinctly worrying.
The signatures he did recognize, however, were sufficiently reassuring to head off any hints of tension that might have otherwise begun to surface.
When Sasuke Uchiha woke up that morning, the first thing he noticed was that he had two arms.
For most people, this would have been entirely reasonable, even expected. But Sasuke had not had a full left arm since his teenage years, when the limb had been blown off in a clash of obscenely high-powered jutsu between him and his closest friend/fiercest rival.
So to wake up with one was... disconcerting, and vaguely annoying, to say the least.
After the end of the Fourth Secret War, Naruto and most of those closest to Sasuke had almost immediately forgiven and forgotten all of his many transgressions between the ages of thirteen and seventeen, ranging from defection, attempted murder, high treason, assassinating the acting hokage, several more counts of attempted murder, and trying to spark a continent-wide revolution.
They were happy to have him back, and liked to pretend that none of that stuff had ever really happened. Tsunade and Sakura had even tried to hook him up with a Shodai-putty prosthetic shortly after the war.
But Sasuke had refused this offer.
Partly, his reasoning had to do with the fact that the idea of replacing his missing arm with a bunch of mutant adult stem cells from a man who had died around half a century ago was just gross. He couldn't even stand drinking from another person's canteen, and they expected him to be fine and dandy with gluing some sort of tree-man corpse-tumor onto the stump of his elbow?
Yeah, no. His fight with Kabuto had left Sasuke borderline paranoid about body modification. That naked chick crawling out of the man's chest and flashing him with her lifeless clone tits had been traumatizing enough. He didn't want to have the stem cells of some long-dead Senju fused to his shoulder.
That would be just a little too Madara for his tastes.
Of course, aside from the Uchiha's squeamishness there was also the underlying motivation of atonement.
He may have been forgiven for most of the shit he had done leading up to the Fourth Shinobi War, and even that halfhearted, almost immediately-thwarted plot to assassinate the Gokage, but he had still done wrong by a LOT of people. Maybe he'd had his reasons at the time, but the man he was now refused to forgive himself all of the awful things his younger self had done.
He had to live with his mistakes, and try to make up for his many transgressions. He did his best to remember all of the wrongs he had done, chiefly so he would never go off and do them again.
He lost his arm trying to kill Naruto – his best friend.
In Sasuke's opinion, replacing that arm would be like saying it no longer mattered that he had attempted to murder one of the only people to keep faith in him all the way up to the bitter end. Naruto had believed in him, and done his damnedest to save Sasuke from his inner demons even when the Uchiha had personally been doing his college best to rip out the Uzumaki's throat.
He had tried to kill Naruto with his left arm. He had attempted to commit an unforgivable sin with that hand.
Dimly, he remembered hearing a bit of foreign scripture in his post-war travels that spoke of cutting off any part of yourself that caused you to sin, saying that it was better to go into paradise a cripple than to suffer eternal damnation fully intact.
Sasuke didn't know about anything else that monk had said, but that much at least had rung true with him. So much so that he had almost attempted to pluck out his own eyes then and there.
The holy man had been highly disturbed by this, apparently having meant his sermon in a much less literal sense than Sasuke had taken it, and only reluctantly had the Uchiha listened to the man's request to please not mutilate himself right in front of the children.
Whatever his ultimate reasoning, though, Sasuke had stubbornly refused to ever replace the arm he had lost. No matter how hard his friends tried to convince him otherwise.
And on at least one memorable occasion, his wife had even secretly grafted on a new arm in his sleep.
It had taken the hungover Sasuke half the day to realize what Sakura had done, that time, and when he did he'd irritably ripped the arm off at the elbow and flung it aside.
Much to the visiting daimyo's distress.
Feeling this new replacement arm, Sasuke figured that Sakura or Naruto had probably taken another shot at convincing him to replace his missing hand.
He did not appreciate the gesture.
"Dammit, you guys..." he muttered, irritably grabbing the offending limb in his hand. "What part of 'I don't want a new arm!' can't you understand?"
Casually, and effortlessly, Sasuke flicked his wrist and ripped off this most recent replacement limb.
It took him a second to register the blood.
And by the time he did, the blinding pain was almost bad enough to keep him from focusing long enough to cauterize the wound with an emergency kagutsuchi.
That was unexpected.
Sakura was the first one to realize she had traveled back in time. Mostly because:
1.) She had woken up in a bed only big enough for one.
2.) She appeared to have been sleeping in her childhood bedroom.
3.) Her childhood home had been destroyed by Pain's big ass Shinra Tensei over a decade ago.
4.) Even if that house and her bedroom had still been intact and standing, her childhood bedroom should have felt much smaller to her adult self.
5.) Her chest was completely devoid of anything even remotely resembling actual boobs.
This last detail was the most telling, because while it was possible that someone could have built a perfect replica of her childhood bedroom and scaled it up to freak her out (which sounded like just the kind of collaborative prank that Naruto, Sai, and Ino might pull off if they were feeling especially bored), Sakura felt reasonably certain she would have noticed undergoing any kind of breast reduction surgery.
Also, whatever this was, it sure as hell wasn't a genjutsu. She'd had enough kinky illusion sex with her husband in his tsukuyomi to know most intimately when something was and wasn't real.
So, adding all of these details together (and taking a peek at the calendar just to be sure) Sakura felt it was pretty safe to say that she had somehow traveled back in time. And judging by the almost complete flatness of her chest, she reckoned that her current body was somewhere around twelve or thirteen.
Fortunately, her chakra reserves seemed to be completely intact, or else this could have been a Very Bad Thing.
As it was, Sakura just hoped she wasn't the only one to have wound up in the past, or else this was going to be a very long, very boring wait.
Hinata was immediately aware of one thing when she woke up:
Her husband was not in bed next to her.
Activating her byakugan, she saw that he also wasn't anywhere in the house. Also, that this wasn't their house.
Half asleep and distinctly horny, Hinata felt exceptionally grateful in advance for being married to one of the most vigorous and generous lovers alive. She also felt very little patience for anyone who might try to get in between her and her husband.
Hinata's feelings for Naruto had strongly defined a considerable portion of her life. Her admiration for his determined spirit had led her to try and improve and overcome her own weakness. Her love for him had led her to take action multiple times in her teenage years, where she otherwise would have stood aside and let someone else come to the rescue.
And the mature, more erotic love she felt for Naruto as his wife had let the former Hyuuga heiress overcome much of her old shyness and bashfulness. She was by no means without shame or restraint, but when it came to her husband she could be shockingly bold.
Which is probably why the first thing Hinata did upon standing up from her futon was to blow through the nearest wall with an over-powered vacuum palm. And also why the second thing she did was to stalk off the premises of the Hyuuga manor, heading as the crow flies straight towards the unmistakable beacon of her husband's chakra.
The fact that this entailed blasting her way through many more walls and branch house members, while dressed in nothing but her (admittedly conservative) pajamas, did not bother her in the slightest.
Hinata Uzumaki had pined over a decade for Naruto before he had finally come to reciprocate her feelings. She was not about to let anything keep her from seeking him out and showing him her love.
Over and over and over again.
Good news: I'm still in Konoha.
This was Naruto's first thought after stumbling his way, half naked, out of that vaguely familiar apartment. He still felt dreadfully hungover, and the open sunlight was like a pair of red hot daggers being stabbed into his skull.
He was distracted from the murderous headache, however (stupid Kurama never letting him use his chakra to fix those fucking hangovers... grumble grumble...) by the sight of the hokage monument.
There were only four faces.
It looks like I'm in the past.
He pinched the bridge of his nose.
This realization naturally put the Lord Seventh Hokage in an extremely foul mood. He had sealed away all those alleged time travel jutsu scrolls for a very good reason.
"I better not be the only one here..." he muttered, dressed in just boxers and an undershirt, looking down irritably at his much scrawnier twelve year old body.
Had he ever actually been this SMALL? It seemed inconceivable.
He was then distracted from his thoughts by a very familiar flare of distinctive fire chakra roughly in the direction of Sasuke's old apartment. It was quite small, considering the sort of things Sasuke usually broke that jutsu out for. Probably no more than a little flicker of flame.
And it disappeared almost immediately too. Humming thoughtfully, Naruto noticed that Sasuke seemed to be in a good deal of pain – physical rather than emotional, for once, although there was a much smaller degree of distress directly associated to that sudden spike of ow.
Cocking an eye curiously, Naruto then zoomed in on Sakura's signature.
She seemed mildly annoyed, but it was well within the standard deviation. People got annoyed all the time over little, meaningless things. Often when dealing with him.
Naruto was perfectly accustomed to that sort of feedback, and it didn't raise any of his eyebrows.
Something he DID notice, however, was a not-so-distant growing throng of slight surprise and confusion, along with a very familiar flavor of desire attached to a chakra signature he knew as well as that of his own kids.
Despite their current circumstances, Naruto couldn't help the cheerful grin that came onto his face. He could tear a new one out of whatever asshole had landed them in the past later. For now, however, he had a frustrated wife in need of some stress relief.
And he could do with blowing off some irritation, too.
"Hello, dear!" Naruto said to Hinata Uzumaki nee Hyuuga. "How are you feeling?"
The twelve or thirteen year old Hinata gave her twelve or so year old husband a curious, but also intense, look.
"...Naruto?" she said wonderingly, having long ago dropped the -kun honorific. If there was anyone she could reasonably address with the intimacy of a first name basis, it was the Lord Seventh Hokage and father of her children.
Naruto sweatdropped, seeing the befuddled expression on his wife's face.
"...yeah, it looks like we're in the past," he commented.
"So... Bolt and Himawari...?" she murmured, her expression falling.
Naruto winced. He squinted, looking a touch anxious.
"Yeah... I'm sure we can find a way back, but..."
Hinata smiled softly.
"They'll be alright for a little while," she whispered. "Until we can return to our own time, at least."
Naruto grinned, and took his wife's hand.
"Yeah... until then," he murmured. Then his expression turned foxy, and he grinned at Hinata. "Want to go inside, m'dear?" he said with a playful wink.
Hinata giggled, and batted her eyes at him.
"Mm, but of course," she said in a tone that would have been quite husky if her present body were capable of producing such sounds.
Naruto picked her up in a bridal carry, and brought her in over the threshold.
Ten minutes later, a very angry and flustered looking Naruto stormed right back out of his apartment. He was fully dressed, now, glaring down at his own crotch, and radiating a generous amount of killing intent.
Those inhabiting the floors below him in the apartment complex promptly experienced an inexplicable, simultaneous loosening of their bowels. One particularly elderly tenant even suffered a brief heart attack, though fortunately it was while their children were visiting, and thus able to get them immediate medical attention.
Hinata came out of the apartment a moment later, still dressed in her conservative, unrevealing night clothes. She was smiling weakly at Naruto, and placed a comforting hand on his shoulder.
"Don't worry, dear," she said softly. "I hear it happens to most men now and then."
Naruto spared a forced smile for his wife, before glaring once more down at his groin.
His eye twitched.
"...I'm gonna kill whoever got us thrown back in time," he growled. "Fuck causality, fuck the laws of nature. I don't even care about that garbage anymore... multiverse theory or some shit, I don't know..."
He threw his head back, then, tearing out fistfuls of his hair and screaming in frustration.
"BUT I AM NOT GOING THROUGH PUBERTY AGAIN!"