A/N: A Naruto SI story. We will be derailing canon as soon as reasonably possible. Don't worry, there will be no play-by-play re-enactment of scenes you've already seen here. I also take the butterfly effect rather seriously. Hopefully I'll be able to make this a world where things happen because they make sense for people to do, rather than narrative necessity.

Now also up on SufficientVelocity and SpaceBattles for all your discussion needs.

ooo

Knowledge is power.

I have knowledge; I want power, now if I could just figure out the exchange rate...

I should probably explain. Let's go back a little.

ooo

A hot day in summer, hanging by my fingertips halfway up the cracked and crumbling masonry of an old bridge over a river near Bristol. An eager look on my face as I eyed the next handhold, it would take a low sweeping leap followed by a quick placement of feet to manage. Miles stands ready below, holding the rope that snakes through my harness and the anchor point. It has been a long day but his eyes still shine with focus. He knows I am relying on him.

Crouch, bounce, crouch, bounce, crouch, leap!

A perfect moment floating through the air towards the craggy hold.

Slap-crunch.

An eternity falling through the air with the broken hold in my hand.

Creak-snap.

The parting of the frayed strands of the borrowed rope, till now hidden within the sheath. A shocked shout from below. The whistling of the wind in the ears of a body hurtling towards terminal velocity.

Crunch.

ooo

Personal Log

For a time there was darkness, then light. I was handled and held by blurry giants cooing odd nonsense in adoring tones. I went under, and awoke looking upwards, lying between thick bars and barely able to move my arms, let alone lift my head. A few brief minutes of panic and again I dipped under the mental waterline, coming to in the arms of another giant feeling warm and protected. This continued for some time.

It was only later, once my eyes started working properly and I saw a Konoha headband on a passing shinobi that I figured out what was going on. I had thought I was reincarnated as a narcoleptic, imagine my joy to realise I had simply gone insane! Much better. I've always held that I would make a fantastic insane person. That brilliant insight didn't last long either: my surroundings were simply too boring to be explained by insanity. If I was going to go insane it would have been more interesting than this. I would have seen to that. So, I was in Naruto. All things considered, pretty good going.

Sure, my life expectancy was about 15 years and change, the village might be destroyed any number of times, respecting human rights was considered somewhere between eccentric and a glaring weakness and so on but I didn't care. Three reasons. One: I would get to be a bloody battle wizard. I don't care what they call themselves or how they dress it up, they are obviously wizards. They shoot fireballs, use lightning and teleport while fighting with golems. Wizards. Two: immortality; this world is within grasping distance of it and I want it. Death is a blight on humanity and I would see it ended. Three: perversion potential. I would have to wait till I was 18 or so and go for older women, but can you imagine what a dedicated ninja couple can get up to with clones and genjutsu? Can you fathom it? I can, and once I have hormones again it was going to be glorious.

Ahem. Anyway, I kept passing out. Naturally a baby's brain cannot support an adult's thought processes. Equally obviously, I was a baby thinking words like 'thought processes' then fading out for hours after every few minutes of thinking and waking up with new memories of acting like a baby. Clearly something funky was going on, and that something could pretty much only be chakra. After a few months real time and a few days conscious time I eventually figured that I was emulating my old brain using chakra, somehow, and because I was a baby with baby sized reserves I could only squeeze in short periods without running out.

So, knowledge and power. Priority one: copy my chakra-brain into my meat brain. I do not want to end up as a secondary guidance personality in some teenager's head who only gets turned on to solve maths questions and give dating advice. Not a chance in hell. I didn't go through death to end up as a glorified Nav Pixie! At the minute there's nothing in there but a bunch of mostly-unconnected neurons and some instincts for crying, crapping myself and looking at shiny things, and I need to get in there before that changes. I wouldn't mind control a person but I'm certainly not above re-seating myself within my own reincarnated body.

The next few months were... weird. All I can say is thank fuck for neural plasticity. This never would have worked on a fully grown brain. Running two minds in parallel thinking the same thoughts is a bizarre and distinctly unpleasant experience. Didn't actually give me twice the thought-power unfortunately, which would have been nice. I knew I'd never fit all the information into my tiny baby head, so I focused on the bits that were important and took savage joy in cutting the rest out. The most important thing was obviously my thought processes. I'd spent years in my last life building those things: polishing and refining and generally trying very hard to build a sparkling tower of diamond-bright thought. On the upside, that made it very hard to lie to myself. On the downside, it was very hard to lie to myself. You never quite realise how comforting and fluffy all those lies are until you remove the ability to believe them. My foreknowledge could largely wait until I was older and had more storage space, it would stay nice and preserved in my chakra-brain until I could finish moving all the bits I wanted over. I certainly wasn't going to bring the thought patterns for laziness across, what would be the point?

I spent every conscious moment inscribing my ways of thinking and feeling into my mind, and gradually as time went on I started being aware of more and more during the times when my secondary mind was offline. I even learned my new name: Nakano Tetsuo. Clear thinking iron man of the central fields. Poets, my parents are not but I was pretty happy with it. Whenever something dramatic happened I could shout KANEDA back at them and completely ruin the moment. It was perfect. Until I realised what it meant that I was a Nakano. No bloodline. I was stuck in Naruto without any bloodline abilities. I was doomed. Excessively doomed. This would need to be fixed as soon as possible. By hook or by crook I was getting me some of those mystic eyeballs. If possible a complete set: blue, red and purple. I'm a completionist, sue me.

ooo

Personal Log

Once I was six months old I had gotten into a pattern. My baby brain was well situated enough to follow basic plans, though not to make new ones. I would wake in the morning, then wake up a second time and give myself instructions for the day, spending as long as I could afterwards copying over new memories and thought processes before I was nearly out of chakra. Then I would drop the brain emulation and spend the rest of the day working on whatever I had thought best with my vague knowledge of kiddy development. Waggling my arms about trying to develop a mind-muscle connection and babbling like a brook that wanted to learn Japanese but only knew goobooglarb.

If something came up I'd re-activate the brain that actually knew how to make decisions, but that didn't happen often. At the end of the day I'd use up all the chakra that had returned to finish transferring my mind over. I was lasting longer by the week. Hopefully the chakra use would strengthen my reserves and not, say, cripple my potential permanently Rock Lee style.

I think I freaked my parents out a fair bit. Babies aren't supposed to spend a whole day clenching hands then arm muscles one by one while making random yet deliberate noises. They certainly aren't supposed to have intelligence suddenly fill their eyes only to look at you sharply, then shudder at the indignity of having diapers changed and fade away again. I was wasting my valuable chakra responding to them! I needed that! I had to get this finished before a real consciousness seated itself or else it wouldn't be me exploring this wonderful and deadly world. Just an incomplete copy. Unacceptable. I had to keep going till I could be happy with it and switch off the secondary brain for good. It wouldn't be good for much once I was done.

Anyway, I had a routine, a goal and the beginnings of a plan. I was going to take this world by storm like a furious Chihuahua with a football. First knowledge, then power. World Domination Optimisation was coming baby! I was feeling pretty good about myself.

Then the Kyuubi came.

ooo

A/N So there's probably not actually going to be much in the way of romance in this story apart from possibly in the epilogue. That up there is just the thoughts I'd think if I were in such a position, not a statement that the story will actually go to such places. I don't fancy writing that and it would feel too egotistical to have an SI go out to get some. So unlikely but not 100% ruled out, though I'd have to do a separate update on Ao3.

The story will be vaguely AU because many things in Konoha just don't make sense and I don't want to leave them in. Feel free to tell me if I've got a detail wrong, but don't be surprised if I respond by saying I like it better that way.

Also it should be noted that the SI is not a completely reliable narrator. His knowledge of canon is weak, and he can be a bit unobservant from time to time. He will occasionally think that the world of Naruto does x when it actually does y, and y may in fact come and try to cave his face in for his presumption in not taking it into account.