For lack of a calculator, I ran the numbers in my head. One half of thirty-seven plus seven. Twenty-five point five. Damn.

Wait... One half of twenty-six, plus seven. Twenty. Double damn.

The half-plus-seven rule, a guy's best friend for figuring out if it was creepy to date someone. If I were actually sixteen, Katsumi would be just outside the safe range, such that by the time a hypothetical relationship started between us, everything would've been cool.

But I'm not a sixteen year old. I'm a thirty-seven-year-old man who's gone through puberty for the second time. And let me tell you, your mind is not made to go through puberty twice. I've developed a sex drive while already having the one from my last life. Yeah. Not fun.

True, I was using the American standard of dating appropriateness, not the Kumo one. Here, the age of consent was a mere thirteen years old. Still not touching her, though.

But, I could always go for older women, right? Well, by the half-plus-seven rule, the youngest women I could date without it being creepy on my end would be twenty-six. But that made me too young for her, physically speaking.

... I'm going to die a virgin in this life too, aren't I?

On the bright side, both Haruka and Katsumi both have nice boobs and butts, and watching them fling them around — I mean spar — is entertaining enough, even if I'll never get to touch.

God fucking damn double puberty.

Training. Focus on training. Focus on the mission. The Chūnin Exams. Those are coming up, and I have to be prepared for the... the finals.

Shit.

I have no idea what the status of the timeline is. Has my existence caused a butterfly effect? I know there was no Hyūga Affair — my existence made kidnapping Hinata a waste of time — and I knew that the Kyūbi had attacked Konoha when I was three, but other than that, I had no idea what was going on.

Would the attack play out the same way? Would it still happen? Hell, was I in an alternate timeline altogether?

No idea. That bothered me.

Worse, I've had nearly twenty years to forget stuff. I wasn't exactly the most detail-oriented fan of the show back when I did watch it, and the series had been over for a while before I actually kicked the bucket. Not to mention the eternity-in-an-instant that I spent floating in the ssʎqꓯ, or the bloodline-induced accelerated mental time I've been living in since being reborn.

Basically, I've forgotten all but the simple shit. The sudden presence of chakra within me when I'd been born gave me the incentive turn trivial memory into an actual skill, but the fact that I couldn't have acted on any other details even if I'd wanted to condemn my memories of Naruto to being forgotten.

So, would the attack play out the same way, or was I in an alternate timeline? How would I know? How could I know?

At least, while I pondered the unknowable, I had a great view of bouncing boobs and butts, in glorious 360°, clothes-penetrating, high-definition vision.

... And now I feel like a creep again. 'Undressing her with your eyes' had never been so literal. And yet the bulging veins around my eyes didn't go away, and in fact, were joined by bulging veins much further south.

Okay, Kenta, focus on something else. Study their chakra, how it flows within their... curvaceous... bodies. How it flows, how it swells, how it fills them up until they're about to burst, how it rises up, and how it finally spurts outward into the world in a final release.

Fuck, now I've gone and made chakra itself sexy... Note to self: research or invent sex jutsu.

Oh, look, here comes Takeshi. I watched him draw his blade and begin his training routine. He thrust, he swung, he infused his chakra into the blade — all things common to training. Of course, my horny and perverted mind started sizing him up as well. Aaannnd... all signs point to the fact that he's going to grow up sexy too.

Finally just giving up, I deactivated my byakugan, blinding myself. My mask only had holes for me to breathe through; the solid metal around my eyes may have protected them, but it obscured the beauty of the world from my mundane sight.

Now blind, I was free to fully concentrate on what I should have been doing all this time: working out. There was still a sense of me-versus-them in our group dynamic, and as such, other than giving me some advice, Sensei had just left me to my own devices while she focused on her younger students.

As she had so succinctly put it, and as our mock battle had shown, I was still rather pathetic at dealing with melee-range enemies. So, having done some stretching and some weight lifting to warm up, I began running through the kata of my clan's taijutsu style as fast as I could. Speed was the key, and at this point, it was more of an issue of mental consolidation than of learning the techniques. In essence, I had to teach myself not to think three thoughts in a row — A, then B, then C — but one thought with all three — ABC. It was also a very different sort of training than learning to use a firearm.

I loved it.

I'm not kidding when I say that I've developed a love for training and physical exertion. I think it's an innate reaction from this body. After who knows how many generations of people fighting, where generations of a single family fought without interruption, the level of natural selection pressure was ridiculous. The degree of difference between a clan ninja and a civilian was startlingly obvious to my eyes.

Eyes which, if I recalled correctly, came from an alien goddess whose own people fought in the same way. At this point, I'm almost certain the relationship between ninja and humans was more like the one between humans and neanderthals than anyone cared to admit.

But I digress. Whatever the evolutionary history of this world may have been, that didn't matter to me here and now. What did matter was this: not only was the runner's-high phenomenon still a thing here, it was far more potent than back home. I mean, a good, hard workout could leave a person smiling all day, and it only took half as much effort to get that high.

... If it's actually biological, then that explains so damn much about this world. We're war junkies, all trying to get our next adrenaline and endorphin fix.

I'm not complaining. Not. At. All.

I finished my katas and activated my byakugan again. Katsumi and Takeshi were sparring with each other now while our team's jōnin watched and critiqued.

Making my way towards her (and ogling her breasts via better-than-x-ray vision), I asked, "Ma'am, are we going to be taking any missions between now and the exams?"

Her dark green eyes flicked towards me, but her head didn't move. "Just D-Ranks. We don't need anyone getting hurt at the last minute. I spoke with the Raikage last night; they're not sending any other teams to this. Konoha might be neutral to us on paper, but things are still tense even this long after the war. There's a lot of politics going on in the decision to send us there. Your clan spent a lot of its political capital getting Katsumi selection for the chance, you were in the right place at the right time, and Takeshi's already got a reputation as an up-and-coming blademaster and swordsman. In short? Nobody's going to risk this."

"Yeah, that's what I figured," I replied. "Just wanted confirmation."

"Good." Haruka's eyes moved back to watching her other, original students. A moment later, she shouted, "More strength, Katsumi. You need to punch through your target, not at your target." Sure enough, my cousin's next punch landed much more solidly than her previous ones, to Takeshi's visible frustration.

"Ma'am, I—"

"You can call me Haruka, Kenta. I'm not very big on formality."

"Haruka, then. I was wondering... If you knew that the world had a very real and very significant chance of ending within the next three years, what would you do?"

She turned and stared at me — not just a look out of the corner of her eyes, but a full head-turn so that she could look straight at me. "What the hell kind of question is that? The world isn't ending."

"..."

"You're a bit morbid, aren't you? This normal for you, or are you in some sort of funk this morning?" she questioned.

"It was just a thought. I—"

BOOM!

Haruka roared, "Katsumi! No explosions in a friendly spar!"

"Sorry, Sensei."

She turned back to me. "You were saying?"

"Nevermind. It's not important."

Ōtsutsuki Kaguya. The Scion of the Entity known as the God Tree. The potential destroyer of the world. I know my presence changed things, and like the flap of a butterfly's wings, that could that Naruto might lose. We'd all be devoured by the tree.

There was always the possibility that the world wouldn't end like that. Maybe Zetsu was dead, or something. This could be an alternate universe, for all I knew. But to make any assumptions was dangerous. If the world was ending, I'd want to know for sure.

"Alright... if you say so."

"Haruka, do you mind if I leave a little early to go practice my jutsu alone?"

"You don't want another pair of eyes?"

I smirked, though I knew she couldn't see it under my mask. "Unless your willing to let me turn you into a pincushion by letting me throw senbon at your chakra points..."

She shuddered. "No thank you. I've fought a Hyūga before. Having your chakra points shut down fucking sucks."

"True." I'd tried shutting down my own chakra points before; it hurt. "But really, I'm fine for now. I'm just rehearsing my existing jutsu arsenal."

She nodded. "Sure. Practice your short-range stuff the most."

I told her I would.

"Masaru, I'm back," I called as I entered my home. Masaru was the man who the clan considered my father, despite the fact that neither he himself nor I considered him as such. His late wife was my second mother, who died when I was physically four, mentally twenty-five. He had no biological relationship to me and technically held no obligation to "raise" me.

When his wife died, I told him about my past life. I started doing the chores around the house — all the chores — until I could start doing D-ranks all on my own and bring in money. Right now, we basically lived as roommates rather than family.

The fact that I could care for myself and didn't need a parent was a massive relief for him. He'd only been twenty when I was born, meaning that chronologically, he was about six months younger than I was. Without that stress of being a father earlier than he'd ever wanted to be one, he was able to get over his grief much quicker.

Twelve years later, we were good friends. Maybe it was just the mere-exposure effect working on two people who didn't hate each other, but we'd gradually grown closer together.

"I'm in the back!" he shouted. Knowing exactly which room he was referring to, I quickly sped to our workshop. It was a room that we'd expanded thrice, including knocking down nearby walls, to accommodate everything the two of us were working on.

I found him hunched over our refrigerator, hands stained with ink, of all things. The brush in his hands was, with supernatural quickness, drawing the arcane symbols of cloud-style fūinjutsu onto the refrigerator's back, all around the coils. The food and drinks that had been in there were stacked neatly on the workshop bench, save for several beers, whose empty bottles were strewn across the floor haphazardly.

I picked up the beer bottles and threw them in the trash. "Whatever you're doing, hurry it up. I don't want that food going bad."

"Almost done..." he muttered, his hands still copying the symbols from a nearby scroll.

I leaned over to see what he was doing. I'd never had the time to sit down and master fūinjutsu, but I knew enough of the basics to see the general gist of what he was doing. "A reverse fire seal, right?"

"Heat to chakra, my friend. Cold beers and free chakra." Well, not "free" as in "unlimited," but free as in "harvested from a previously inaccessible yet still finite resource." Though now that I think about it, I have no idea if chakra obeys thermodynamics or not.

"How efficient is it?"

"Horrible. Only about 15% efficiency. Better than my last draft. Bah, whatever..."

"Have you considered light to chakra?"

He stopped, literally freezing with his arm suspended in air. "That... Could that work? Don't know how yet, but I don't see why not." He looked at me. "Great idea."

I sat down in my chair, pulled off my mask, and grabbed one of the still-full beers for myself. Old enough to kill, old enough to drink — that was the ninja way. I didn't even like beer, but I was a happy drunk and my thoughts had been all over the place today. Getting mildly drunk in my (technically Masaru's) home was just what I needed.

As I sipped my bitter beverage, I watched Masaru put the final touches on the refrigerator's seals. Then, he clapped his hands, gathered his chakra, and poured it into the seals.

Yes, the blood in the ink manipulated the chakra in a way that was almost hypnotic to watch, but for every single change the seals made, Masaru himself made three more. That was the real reason fūinjutsu was so hard; it was a jutsu. There were no hand seals, but there was something external shaping the chakra alongside you; to use a fūinjutsu, you had to compensate for that.

It was a beautiful thing to behold. The seals twisted and shrank, growing in complexity all the while. Then, with the visible equivalent of a click, the jutsu snapped into place. "That never gets old."

Masaru smirked. "I live to entertain. Can you check it over for me?"

I did, using one of my self-invented jutsu to narrow my byakugan's field of vision in exchange for greater clarity. "You have some turbulence around the seven o'clock T-junction. It's increasing the resistance in the counterclockwise flow."

He blew a strand of his pale blond hair out of his eyes. If he'd been a redhead, I'd have wondered if he were an Uzumaki. "That's where I thought it would be. Good to see I was right. No idea how to fix it yet, but at least... Wait, turbulent how? Vortices or oscillations?"

"The former. It's spinning."

He nodded his head once. "That makes sense. Alright, maybe if I..." he trailed off.

Seeing a need to speak before he got too involved in his seal crafting, I asked, "Hey, do you mind if I work on my guns? Will the noise bother you?"

"Nah, go ahead," he replied without looking at me.

"Cool." I moved to my side of the workshop, snagging my beer along the way and downing a few gulps. Unlike Masaru's side (which was covered in books, scrolls, ink, and scorch marks), my much larger section was full of metalworking tools, metal, woods, rubber, and an assortment of other mechanical bits and bobs. Any space not filled with tools was filled with the products of those tools.

Bows, crossbows, senbon launchers, kunai launchers, shoulder-mounted railguns, tripod-mounted railguns, actual gun guns (just a few prototypes, and they still tended to explode), thermite, sugar rockets, and puppet parts designed to carry all of the above. Almost every single thing here was designed to either be triggered by my lightning chakra, or be augmented by it in some way.

My pride and joys, among all of my creations and purchases, were my railguns. Once I'd engineered lightning chakra-compatible ones, the true power of my byakugan was unleashed. While there was no fucking way I could engineer something to the same standards as the U.S. Military, using the ninja bullshit that is chakra and seals, Masaru and I had created a weapon that could put a metal slug through someone's brain at ten miles.

Oh, and that? That's the basic one.

The massive one shoots beyond my byakugan's range. That jutsu I mentioned earlier, the one that let me sacrifice field of view for clarity? I could also sacrifice field of view for range. Tunnel vision for greater clarity at a distance. I could extend my sight to up to thirty miles — a view so long that I had to look through the Earth itself to see my target. Targets that far away were equivalently five hundred feet underground.

The slug from the big cannon overshot even that enhancement of my vision.

I couldn't carry the damn thing, not even with ninja strength. The only way to move it was with storage seals, and those took an annoyingly large amount of chakra to seal the mega cannon away. But firing it? That took a surprisingly small amount of chakra for what it was — still huge, but not that huge. Big and flashy jutsu have a ridiculous amount of energy waste; for a simple Uchiha clan fireball, how much of the giant flame actually hit the target? Twenty, maybe thirty percent? And that's a genin level jutsu. What's more, the sheer size of it means that the destructive energy is hardly concentrated.

A gun is so much more efficient, even when Newton demanded that half the energy was lost in simple recoil. My theory was that the more bullshit a jutsu involves — the more it screws physics in the ass — the more chakra it takes, and that the actual observed energy requirements don't factor into it all that much. I mean, why else would one shot of my mega cannon take only as much chakra as holding the rasengan for five seconds?

Yes, I knew the rasengan. Anime Jiraiya taught it so well.

Anyway, back to my original point: my section of the workshop was an utter mess... Thankfully, I had über-hax eyes to see through all the clutter. Burning a little extra chakra for my other bloodline, I sped up to about 4x normal rather than my usual 3x. An extra 33% more time to work on something was no laughing matter. I had guns to fix, ammo to make, and a puppet to upgrade.

I'd already burned through 1/5 of the time I had pre-exams just training with Haruka's team; I needed to get my latest round of projects battle-ready as soon as possible. Flicking out a thread of chakra, I snagged a wrench and pulled it to my hand. Then I got to work.

Chakra amplified everything.

No better place is this more evident than in the hospital. If you just so happen to compare patient charts, you'll notice that for similar injuries, ninja have an estimated recovery time a quarter of what a civilian would have, or better. Wounds close, flesh regenerates, cells repair — a person's chakra bends reality in subtle ways to keep them alive, healthy, and happy, and that's before you account for healing jutsu. But chakra, affected both by psychology and genetics as it is, also evolved to help its wielders in other ways.

For instance, it inspired physical changes in the body. Ninja were tougher in ways that couldn't be accounted for by simply working out. Their bones grow in slightly different shapes and were far denser, their muscles were more powerful pound for pound, and their organs all had subtle adjustments. I knew some of that wasn't entirely genetic, because even civilian-born ninja had these changes, the degree of which almost exactly corresponds to the age they'd unlocked their chakra. (By that metric, it made sense that I had the most pronounced changes of anyone I'd ever seen).

And if you needed more obvious proof... let's just say it's not wise to get into a literal dick-measuring contest with a shinobi. Sex is a big part of life, and chakra amplifies life itself.

The reason I bring this up is because I'm making one last "drop-off" at the hospital's fertility clinic before the start of the exams, doing my duty as a breeding stud. I have mixed feelings about it.

The pros:

I'm a fucking, breeding stud. I get paid to jerk off. I have an extremely sexy body (in comparison to my old life) with a ten-inch cock that can produce a huge amount of spunk. I'll have a shit-ton of kids (fifteen and counting so far, 8 for whom the byakugan bred true). I'll be a branch clan head one day. It's almost like something out of an erotic novel.

And the cons:

I'm a breeding stud, a mere tool to be used. The process is extremely clinical. Being a clan kid means I'm already rich, so the pay doesn't actually mean all that much. I have no choice to opt out of breeding the byakugan or leading the new branch (not that I would opt out; merely the fact that I lack the choice annoys me). And worst of all... I'm only slightly above average-sized among ninja my stature.

You'd think being able to shoot lightning from the fingertips would be enough for a guy, but no. Reality sucks, even in a porn-friendly world.

One round of self-pleasure later, I handed the large, capped vial full of semen to the nurse, who signed off on my log and sent me on my way. I knew that my pay would show up in my bank account by the end of the week, so the entire interaction went by with little more than a "Hello again," between the two of us.

As I was leaving the hospital, I couldn't help but notice who's coming in: Killer Bee. I'd never met the man, but there were only two people in this village who had chakra that shined like a star — and the other was a woman. Chakra like his was unmistakable.

When people compared someone to a bijū in terms of strength, they really meant that the person simply had a lot of chakra. Even the biggest chakra powerhouses were still human, with quantities of chakra that were comprehensible.

The star of chakra inside Killer Bee's seal was not comprehensible. Imagine the sky at night, an infinity so vast that your mind simply has no frame of reference, one that it instead sees as a massive but smooth dome upon which the star-dots are painted. The sky's so massive that the only way to understand it is to imagine it closer and smaller than it really is.

That was what staring at the eight-tails' chakra was like.

I turned my attention away from the man and towards the situation. Bee was in the hospital, and he was hurt. A broken leg, I think. Between his jinchūriki healing and the medic ninja magic, he'll be back out in less than an hour, I'm sure. Hell, they hadn't even touched him yet, and I could see, in real time, his body already trying to fix itself.

I was curious as to how he got it, though. Broken bones were extremely uncommon for ninja outside of fights — we're naturally tougher and better able to escape dangerous situations. Leg breaks were even rarer, as chakra can protect from fall damage. Bee didn't look to roughed up other than his leg, so maybe it was an accident.

I don't know. I didn't ask.

I walked right past him. I nodded hello. He casually nodded back. We didn't speak at all. And why would we? We've never officially met.

Killer Bee can wait. I've got a mission to prepare for.