ANBU Since Birth
Naruto didn't get on with the children at the orphanage. They wanted to play, there was no purpose to play, play wasn't going to get him closer to his goal. They complained incessantly, complaining wasn't going to make their lives easier. Naruto viewed them as frivolous, they viewed him as weird, he was ok with that.
The matrons quite liked the situation, they didn't even have to show the children that they should alienate Naruto, it all happened by its self.
There were only two things Naruto liked about the orphanage, he had a lot of alone time to train what he could, and they had a library.
Actually, 'library' is stretching the word, what they had was introductory books to most subjects that someone would need through their first year at the academy, and a lot of introductory books for civilian trades, most academy students used their stipends to move out after a couple of years, but those that went to civilian schools tended to stay till they were twelve or even older. Because of this there were a lot more books on things that civilians found important than there were for shinobi activities.
So Naruto read mathematics, geometry, finance, the basics of several crafts from the civilian section, and the basics of throwing, how to stretch and exercise, how to train balance and taijutsu, chakra meditation and control, the fundamentals of stealth and emotional conditioning.
The matrons wouldn't have allowed him into the library, if they had known he went there. That had been one of the first things he had started doing when he arrived at the orphanage, covert reconnaissance, using it as a means of training stealth as much as he could.
With Naruto
As soon as he could he began doing chakra meditations, finding it, making it circulate, controlling it, bending it to his will. This led to the first meeting between Naruto and the Kyuubi. Fortunately, this was not really all that much of a surprise for either party.
During meditation he'd been drawn towards his center, following the spiraling pattern all the way in, until he'd found himself somewhere else. While obviously unique in design, the room was clearly modeled after his time at ANBU HQ, the only place he really had to base his mindscape after really. The mindscape might have belonged to him, but the giant cage certainly did not, it was made of gold and brightly illuminated, not something that would have come out of his subconscious in a million years.
"Greetings Naruto, welcome to my cell." Said the Kyuubi, knowing the value of a good first impression.
"Good morning Kyuubi-Sama, I apologize if my existence is inconveniencing you."
"Sama? No one has given me proper honorifics in three hundred years! And even back then, they were just trying to sucking up to me."
"You are a lord of demons, and as such deserve the honorific. Beyond that you are an elder, older than any man, such wisdom and experience is deserving of the proper respect."
"Ha! When you were an infant, I set about to turn you into the perfect shinobi avatar for myself, but I never expected that I'd get this lucky."
"Avatar? You wish for me to act as you would, given human form? Forgive me for saying so Kyuubi-Sama, but given what I know of your past, that does not mesh well with my future plans."
"No, no. All demon hosts represent their demons in the world, people associate the demon with the human, and so how the host acts affects the demon's reputation. And right now, as you so kindly mentioned, my reputation is in tatters."
"How do you mean?"
"Right now everyone in the world thinks that I am a mindless mass of wanton destruction and hate. They base this off of four things, first when I got involved in the fight at the valley of the end, second and third are your predecessors who blamed their horrible anger management issues on being my host, and fourth is this last attack on the village itself. Right?"
"Ok?"
"But what people don't know is that for both of the attacks I was controlled by an Uchiha. I mean think about it, sure I hate Konoha since everything bad that has happened to me for the last century has been their fault, but I am a kitsune I am not going to attack head on just smashing things with my tails and uncontrolled blasts of destruction, that's the way Uchiha fight, so that's how I fought when I was controlled by them.
"Though to be fair, my previous hosts were driven insane by my chakra and that is part of why they acted so poorly, but I made sure that the same thing won't happen to you so don't worry."
"I had wondered about the discrepancy between your actions and those of other kitsune, I had just assumed that it was because you were a demon with a form similar to that of a kitsune rather than a kitsune proper. So what would being your avatar entail?"
"Not just avatar, shinobi avatar. You only have experience with ANBU, so you might not really understand this, but most shinobi in the world are fakes."
"Fakes, Kyuubi-Sama?" Naruto asked
"What I mean is that they don't act like shinobi, they are soldiers, brawlers, demolishers, medics, bureaucrats, but very few are shinobi like your ANBU, like the shinobi of ages past. Hiding in the shadows, killing with the least possible effort or fuss, doing whatever was needed without complaint. Once chakra use became ubiquitous, the real ones just got lumped in with the imitators."
"So you want me to be a real shinobi, in other words, you are prepared to help me with my goal of getting back into ANBU."
"Do I tell him the truth about that or not?" Thought the Kyuubi. "Yes, I'll do whatever I can to aid you in your goal (He's too young to take the hit and keep on going just yet, in another year to two maybe) I should probably tell you now thought, what I can teach you is limited. I can't perform human jutsu and you can't perform demonic ones, I've never had all that much use for martial arts even when in human form, but I have a good memory and can give advice based on watching others. Also I can advise you on your behavior, actions, choices and have a cunning and creative mind that can come up with solutions you might not."
"I look forward to learning from you Kyuubi-Sensei."
That meeting set the tone for all their future interactions, Naruto didn't really care that, given the option, Kyuubi would destroy Konoha, it simply wasn't relevant to his current situation.
General Perspective
Naruto's constant drive to succeed, lack of distractions and immediate feedback from the Kyuubi accelerated his learning curve, he'd probably have to wait six months to a year to start training in more of the physical aspects because his body simply wasn't ready, but in the meantime he could stretch and work on his coordination to shorten that timeframe as much as possible. He had been learning the chakra sensing and suppression that he'd witnessed the new recruits practicing at HQ, but Kyuubi introduced him to the 'Kyuubi Host's Special Technique', sensing intent. When Naruto asked why he should learn both if the intent sensing technique was so superior Kyuubi replied
"Redundancy, there are skills that can nullify youki, thus blocking your intent sensing skills, and there are skills that can get past sensors, but I know of no skill set that can do both at once."
On several occasions the Hokage came to visit him, these 'surprise inspections', as Naruto could only think of them, were incredibly stressful for him, he couldn't help but wonder "if my body is in shape enough, if my chakra is even enough, if my emotions are controlled enough, if I am polite enough he might let me go back" and then the inevitable disappointment when he didn't get transferred.
Then there were the little tests the Hokage would give him
Flashback
The Hokage walked into the orphanage yard and was immediately met by just who he came to see.
"Oh, good morning Naruto"
Naruto quickly jumped to the alert and bowed low
"Good morning Hokage-Sama"
Trying to break up the mood, Sarutobi said "You don't have to call me that, why don't you call me gramps?"
Naruto looked at him blankly but inside he was horrified "That would be improper Hokage-Sama"
"Ha ha, have you had any luck making friends with the other children since last time?"
"No sir. The others lack seriousness of purpose; forming emotional bonds with any of them would not provide any mutual benefit."
Flashback End
Eventually the visits became less frequent as the council took up more of the Hokage's time. Never the less such trials stripped him of his childish reliance on optimistic expectations, pushing him even further towards realism and pragmatism.
Naruto was kicked out of the orphanage when he was three.
"Come here boy, your leaving today. We've put up with you long enough, I've seen you can take care of yourself perfectly well, so you can take care of yourself somewhere else.
"Leave? But if Hokage-Sama put me here on probation and now I'm being forced to leave. Then does that mean that I failed? That it's over? That I'll never get back?"
Mistaking his look the matron said "Don't look at me like that! There are children in water country that would kill to live on our streets."
Still confused as to whether or not his dreams had been shattered he wandered out of the front gate.
Kyuubi seeing what was going on had to intervene
"Naruto wake up!"
"Kyuubi-Sama, what do I do? It's all over"
"Listen to me and do exactly as I say. You aren't safe in this village right now, it's early morning but people will soon come out to start their days. Run to the nearest storm drain and climb in, you have to get out of sight right now, and the only way to do that without risking exposure is to get underground."
Still too out of it to think about what Kyuubi had just said, Naruto rushed to do as he was told. He ran around to corner and found a sewer entrance that he could just barely lift, with the Kyuubi helping, and climbed down, pulling the lid closed behind him.
"The sewers? How is this any better than the streets?"
"Not just the sewers, in Konoha the sewer system is tied into the tunnel network, there are bunkers and warehouses down here that have been forgotten for decades, they were much in use during the time of Mito Uzumaki my first host. Now pick a direction that looks to be going downwards and start walking and I'll answer any questions about what just happened.
"Am I out of the running to be in ANBU?"
"This is one of those hard truths" The Kyuubi began, but Naruto was already mentally preparing himself for rejection.
"The truth is, you were never in ANBU. It's something that you could have figured out yourself given time, but would probably have taken years to really question on your own. A lot of things from early childhood are like that."
Naruto's world rocked for a moment, he was prepared for one terrible utterance, but had gotten totally blindsided by another. He stopped walking and just stood there for several minutes. Finally he said
"I see"
"This is actually not all bad for you, you know. After all, it means you have a blank slate; you aren't a former member that has proven their way back in past charges of instability, incompetence, drunkenness or anything else, you can be like all the other ANBU hopefuls out there. It'll be much easier to get this way I'm sure." said the Kyuubi trying to motivate him again.
"That's true"
Finding a break of the tunnel leading downward Naruto started to pick up the pace.
"So what was all that about getting underground, why was it so urgent?"
"Naruto, I didn't expect to have to tell you this for a little while yet, but while you were relatively safe in the orphanage, you are not on the streets of Konoha. You see, you know one of my talents is that I can sense intent? I can tell you that if you walked in public up there would be beaten on a daily basis, starved and humiliated, all because they see you as a representation of me. It really wouldn't be possible to be just another face in the crowd; your looks are too unique and flashy to ever blend in. The village, from here on out is to be considered enemy territory."
"Yes Sensei! So what's the plan?"
"First we need to find a base, even if it's temporary, then we'll rest for the day and when night falls sneak up to the surface and break into the academy."
"The academy? why?"
"You can't spend the rest of your life as a mole, and you can't go above ground looking like you do. So we need to get the henge no jutsu, plus any others you can find but the henge is our priority."
"But won't people be able to sense a henge if I walk around a ninja village with one on?"
"No. A henge causes a temporary physical transformation, but the chakra that does it in inside of you and is your own. It would take an incredibly talented sensor, or a Hyuuga to tell if it was applied, and they don't go using those skills on the general public whenever they like."
He walked for several hours, taking random turns, occasionally the Kyuubi would suggest a specific route. Eventually they came to a chamber, only about three stories from the surface, that looked thoroughly abandoned, but at onetime must have been a bunker given the food, weapon caches and accommodations.
Naruto spent the remainder of that day cleaning, sorting through the place, placing basic traps at the various chokepoints and napping.
When night finally came he was ready for it, he made his way to the surface and crawled out of the drain as quietly as he could. He didn't know exactly where he was, but he did now that the city was originally designed in a semicircle with the major streets all radiating out from the Hokage monument and the academy was right near there.
Some people might think that the whole district around the Hokage tower would be heavily patrolled, except that the official shinobi buildings were designed to let intruders in and then trap them there, making it impossible to get out of again, so all the guards were on the inside.
Naruto didn't have any trouble on his way there, there weren't too many people out, and as of yet, they didn't know exactly what he looked like, while at the same time he kept his head down so they couldn't see his face.
When he got to the academy he only recognized it because of the sign, he decided to check the windows first, when none of them would open he went over to the trash and found a piece of wire that he used to jimmy open the latch on the window and climbed in.
The shinobi villages weren't too worried about people stealing from their academies, there was nothing all that unique to the village in there, and if a rival wanted to find out, all they needed to do was ask a spiteful academy dropout with a good memory. The only reason the villages put any restrictions on access for the basic three was so that not just any random civilian could get their hands on them. By restricting access they raised demand for shinobi work and increased the shinobi mystique.
He walked around checking classrooms, but he didn't find anything until he came to a storage room, inside they had basic jutsu scrolls, teaching aids and writing utensils. Quickly thinking it over, he decided that they might notice if too many scrolls went missing, using a pencil and paper he unrolled the first scroll and started copying down the relevant parts.
It only took him five hours to copy down the basic three, plus the additional chakra control exercises and look through all the teaching aids for any additional advice to help him with them. By the time he was done he had a serious cramp in his wrist, but there shouldn't be any solid evidence of his presence.
He left the way he had come, out the window. As he went he positioned the latch so that it was part of the way out, then closed the window and jimmied the latch closed again.
It was difficult to keep calm on the way back, it was seriously dark by now, being a little kid out alone at night would draw most people's attention and that would make people want to interfere with him. He decided to take a risk and go underground as soon as he could, then try to navigate his way back to where he came up by peeking up the drains. This safe, but time consuming, method took the rest of the night. When he finally got back to his base he was so tired that he almost set off his own traps. He collapsed on the bed and slept.
The next day got started on trying to do the henge, he could do it a little bit after only a couple of tries, but it took many more to get his imagination thorough enough to make it passable. When he got that down they started designing Naruto's look.
"…but Kyuubi-Sensei, shouldn't it look as average as possible so as to not attract attention?"
"Naruto you have much to learn, in a world that has the henge and is filled with shinobi, a perfectly average person is the first to attract attention. What you need is something that observers will write off, if they can associate you with something unrelated then you can use that to your advantage. That reminds me Naruto, while you were on your way to the academy you were walking behind a kunoichi out drinking"
"Oh, was I Sensei? I assume this has something to do with our current conversation."
"Yes, she had quite interesting features, dark red eyes, not like those Uchiha ones I described to you, pale skin and wavy black hair. Someone had asked her about it and she had said that it was a family characteristic she had gotten from her father, and that he had died during my attack on October 10th."
"I see, so you want me to take on some her features, and then use her father's death on my own birthday to explain away my existence in the village? Not a bad plan. Even if people do notice me they will write me off as the bastard son of a dead shinobi, and the fact that the family has lived here for at least two generations will make so that the features aren't totally unique to those who see them. Also, while those looks probably are quite striking on a young woman, they wouldn't be too odd of a boy, more understated than anything else."
"So pale skin tone instead of your oddly tanned one, two tone red eyes, lose the whiskers, black hair with a bit of curl at the end, and a thin build designed for speed and flexibility. Let me construct an image in your imagination so you know what to shoot for.
"Good, now we have to talk about your age, it'll be a problem. You are too young to go unnoticed by the public. What age we make the henge will depend on what we plan to do with it. Right now all you need to do is go to the library or the store without being bothered, during the middle of the day, so I think two years older should do it for now, you're three almost four now, so aim for about five."
So Naruto trained to perform that specific henge perfectly every time with the minimum possible chakra expenditure and waste.
With Danzo
He was reading over the reports when his lackey used a shunshin to enter the room
"Danzo-Sama"
"Yes, what it is?"
"The alarm went off in base eight, I was dispatched to investigate."
"and what did you find?"
"It seems that the Kyuubi jinchuriki has taken up residence there Danzo-Sama."
"The jinchuriki, wasn't he living at the orphanage?"
"I looked into it; it seems he was kicked out yesterday morning sir. There is one other thing."
"Oh?"
"It seems that he's taken an interest in learning the shinobi arts, he was practicing the leaf sticking exercise and the henge when I last saw him."
"Oho, it seems he is an early bloomer then. Did you see any other techniques lying around?"
"Yes sir, five in total"
"So enough for everything chakra based taught in the academy then. Keep a discrete eye on him, if he is serious in his training and goes beyond chakra basics into other fundamentals then we'll give him some aid."
"We're not planning to induct him into Root?"
"Of course not, the moment Sarutobi realized that the jinchuriki has gotten skilled when he wasn't looking he'll suspect us. If there is any trace of direct Root involvement he'll flatten us, so instead we'll be indirect. After all, a powerful jinchuriki is good for the village."
"Yes Danzo-Sama" said the lackey before leaving in another shunshin.
With Naruto
It took three days of effort to get the henge to a passable genin level, the transformation was perfect and the chakra use was acceptable. Of course he was aiming at a specific single image rather than using the skill fluidly so it was easier to perfect. When he finally got it down, the Kyuubi called Naruto into his mindscape.
"Now that you have the henge for your new look down we are going to make it flawless and undetectable. Your major problem right now is that your body is too young and frail to take any real training you want to give it. A little known fact about the henge is that, if used constantly for several months while a person is still growing, it will cause that person to actually look like the henge does. Only most kids can't pull this off. The only group that had this problem was prepubescent spies during the clan war period; they would wear a henge for sixteen hours during the day for months on end and then eventually found that they were stuck that way.
"The problem with this is that you can't use another henge on top of the one you are already using, you would have to disengage the first to use the second. So to get around this we'll use what is called a henge seal. Basically what it is, is a seal that makes a henge so much a part of you that sensors, the byakugan and the sharingan can't tell it's there, and you can use another henge on top of it. I know about the seal because Mito Uzumaki came up with it, taught it to her granddaughter Tsunade who talked about it with Kushina Uzumaki, so I got the information from two directions.
"The reason we're in your mindscape is that seals used on yourself, while generally placed on the skin, can be placed directly in the mindscape instead, and since we don't have any way to get a seal done on your skin we're doing it in here."
"Alright sensei, just tell me what to do. I can't wait to start doing more physically intensive training."
"Seals are just pattern of chakra flow that produces a matrix which in turn creates an effect, in essence 'jutsu on paper'. What you need to do is create two patterns on any wall in your mindscape out of your own chakra" The Kyuubi said creating an image of a pair of seals. "And then while doing that, will it to be absorbed into the wall the one on the left first, then the one on the right. Good."
As soon as the first seal had been activated a wave seemed to radiate, like something long restrained had snapped, then when the second activated he could feel the jutsu settle into place.
"That felt odd, should applying a henge seal have really felt that strange? "
Dismissing the thought, Naruto turned to the Kyuubi expectantly
"Kyuubi-Sama, I know that I am training to be strong so that I can achieve my dream, but won't I have to go through the normal procedures to get there? What about the academy?"
Putting his chin on his paws the Kyuubi thought for a moment
"Yes, you're right you will have to go to the academy. When you were there did you happen to see a schedule for the school year, like when it begins and when admissions end?"
"Hmmm. Sort of, there was a flyer in the lobby, looked like propaganda but it did have those dates printed on the cover. I think it was about four months till the start of term and two till the cut off. Even if I look five I'd still look a year younger than most of the new kids. On the other hand, I remember in the orphanage how some of them were saying that anyone could sign up but parents had first right of refusal which is why so many orphans went to academy as soon as they could pass the entry requirements."
"Do you know what those requirements are?" Asked the Kyuubi.
"No, I never bothered to find out at the time, but they can't be too arduous. Given the level of intelligence and dedication of most of those at the orphanage it's probably a physical exam rather than anything complex."
"You're probably correct. One thing to watch out for, if you want to remain undetected is how well you do in the academy. I understand that so called 'geniuses' take only one year to get through and are always at the top of their class at everything, if they want to get into ANBU nobody makes a fuss, but they are also like the public face of the organization. You, on the other hand, I think should take three years, and be near the middle of the class. What you excel at or not really depends on if you want no attention or only the right kind of attention."
"What kind of different scores do you think would get me different results?"
"If you want observant superiors to know you could do better but hid your skills, then be a perfect average with zero deviations. If you want to hide completely then be fairly average with some deviations. If you are aiming for a specific type of teacher and team when you graduate then be mostly average but with one or two areas that you show great skill with and a few areas that you intentionally fail. For instance you don't like flashy jutsu, so don't look like you are good at large scale stuff or elemental ones, instead show talent for skills that highlight what you want."
"I see what you mean. Do you think I'll have to change my name so I can remain undetected?"
"Well, when I was sensing for hostile intent yesterday morning, all the negativity was aimed at 'Kyuubi' 'Uzumaki' 'jinchuriki' and 'whisker marks', it seems that almost no one remembers your given name, or those that do don't harbor you any serious ill will. So if you register as just Naruto with no last name, not uncommon for an orphan who doesn't know his parentage, no one should notice you."
"That's no problem, I remember my ANBU guardians saying that Uzumaki wasn't even my real last name; that it was given to me as a title because all your other vessels had been Uzumaki before."
"I couldn't tell you I honestly have no knowledge of your parentage. I was sealed in Kushina Uzumaki before and had access to some of her memories, but since she mixed her 'love' and 'torture Kyuubi' together in all our interactions I always steered clear of any memories even remotely associated with that emotion. I don't know the names of any of her boyfriends, if she was married or even if she was pregnant (I was sealed in her soul not her body)."
"Anyway, that's more or less the next four months planned out, two months to get used to the new body, do the entrance exam, all while training in what we can get from the academy and the main library, and them start the academy in four months. Feels good to finally be back on track again."
"Fine, fine. For the next few days I want you to lay off the chakra use to let your body get used to the changes. Focus on physical activities and fundamental skills, go back to the academy and copy some more scrolls if you have to."
AN: That part where Sarutobi asks Naruto to call him by a nickname and Naruto says that that would be improper, that was pretty much taken from Rathanel, but I changed it as much as possible to try and keep it from being straight plagiarism. I would have tried to do something else, but it was perfect for showing that he took the 'ANBU are always polite to everyone' thing to heart. This is mostly because I'm sick of Naruto calling the Hokage 'jiji' or Sasuke 'teme'. Even in fics where he is serious minded and the like, authors degrade their own characters by having Naruto lower himself with petty insults and calling people familiarly.
Those whiskers are a massive plot hole.
When I was writing how he was going to look, the first time I read it and said "Gah! I just described myself. This isn't a Self Insert." The second time I was going for a look similar to the Hozuki clan but then wondered why anyone would want to read worthless descriptions. So then I had the bright idea to make him look like a Yuhi, which does have plot implications later by the way.