I tried to focus in my classes, I really, really did. But Yoshiro-sensei wasn't exactly the most dynamic speaker, and I didn't need to hear about tips and tricks to help with addition. It was boring, and I hated being bored even more than I hate waiting for things. Though, I suppose, the second is merely the root of the first.

And the window was calling my name. We didn't have assigned seats—strange, given Yoshiro-sensei's overall vibe—but I sat farthest from the window just to remove that temptation. For all the good it did. It was windy today, as it often was. I could tell from the movement of the singular tree outside. Probably some breed of pine—it had needles. Is that what they were called, in reference to trees? Breeds? That's probably not right, but I don't have Google to tell me the answer. Wow, it's windy. Probably had something to do with the mountains; cities were usually pretty windy in the center too. From all the skyscrapers. And mountains were the first skyscrapers. Au naturale. It reminds me of Chicago. I had only been once; I took the train to Colorado for a wedding, and there was a layover in Chicago. It was only an hour and a half long, but the people at the station were kind enough to watch over my bag (people who actually worked there, not randos), and I went to visit the Bean. I know the artist doesn't like people calling it that, but I'm pretty sure he's an asshole, so I don't give a shit. Didn't he try to copyright a color? That's bullshit. But anyway, I went to the Bean, and there was a stand there that sold Chicago dogs. Great placement, by the way. It probably sees more business than any hot dog stand in existence. Except maybe for ones inside of sports arenas. But those ones are probably closed whenever there isn't a game, so maybe it does see the most business over all. Anyway, the Chicago dogs? Pretty dang good. I was surprised; those peppers they put on them? Star of the show. They really added a depth of flavor most hot dogs lack. The thing is—

"Imai-san?"

"Twenty-eight!" I blurted out, and cursed internally. The problem on the board was 14+14, so I was right. But I bet I just fell into that cliche—he asked a normal question, and I responded with the answer to the problem on the board, proving that I wasn't paying attention. God fucking damnit!

"...correct," he said.

Thank fuck. I sat back in my chair, relieved.

"Who else, besides Imai-san, already knows this material?"

God damnit after all. Several hands raised.

"Iwa does not waste its shinobi's time," he said seriously. "For the rest of this class, those of you who have raised your hands will prove your proficiency. Impress me, and I may grant you independent study time during this period. Take out a blank sheet of paper, and number one through fifteen in a descending column. The others, sit quietly and watch."

We did as we were told, and I felt a thrill of excitement. Every learning institution I had ever attended in my previous life made me sit through an entire course's material, even if I knew it already. No one had ever let me test out of something; at least, not in this manner, and not at this young an age. It's crazy that, in this world, I was given more autonomy at four years old than I was as a teenager in my old one.

"Here's how this will work," he said. "I will ask a question, and you will write down the answer. I will grade them, and if you are correct, you will move on to the next one. If you are incorrect, you will be eliminated. Of course, the difficulty will increase with each question you answer correctly. To speed things along, all of you come to the front of the room, and bring one of your other notebooks to write on."

We did as instructed.

"I hope that none of you have lied," he said cooly, "because if you do not get the first five questions correct, you will face consequences. They are all basic addition and subtraction—topics that you have declared yourself to have a complete knowledge of."

Those in the running, aside from myself, were Chinen Satoshi, Doi Hayato, Go Yosuke, Hirose Daigo and Ishii Masaru. I didn't think Sensei had to worry. Satoshi, Yosuke and Masaru were all civilian-born, raised to run their family stores one day (if only their parents weren't so greedy). And Hayato and Daigo were just smart; anyone could see that.

"First question," Yoshiro-sensei declared, writing on the board behind him 18+9.

I hastily jotted down 27 just as my peers did, revealing my answer when directed.

"Imai-san, correct," he drawled, and I realized with a start that he was going to reveal each of our results out loud, for all of the class to hear. If I wasn't so confident, the prospect would have been horrifying, and I could see the nerves on the civilian-borns' faces as they realized the same thing. Hayato and Daigo gave no reaction. Everyone was pronounced to be correct.

"Next," he said, writing 37+4

We were all correct again, as we were with three (12-4), four (21-12) and five (86-69).

"So you were all telling the truth. Good," Yoshiro-sensei said. "Now, let's see where all of your true capabilities lie."

5X5.

Some of the people behind us had probably never seen a multiplication sign before. We all answered correctly.

13.25X8

Well, there was a slight jump in difficulty. But we all managed to answer correctly, though I was the only person who was able to do the math in my head.

"Well done," Yoshiro-sensei said in a tone that I couldn't tell was genuine. "Next."

864X1386

That even I needed to work out on paper—very few adults could themselves, in my old world as well. I began to write quickly, my pencil flying over the page as I worked. I kind of bit myself in the ass here; I didn't put enough space in between problem numbers. I should have known Yoshiro-sensei would ask genuinely puzzling questions. And this was only eight out of fifteen!

Graciously, he gave us time to figure out the answer, more time than I needed. Still, his patience ran out eventually.

"Ishii-san, Go-san," he intoned. "Do you have an answer?"

"Gomen, Sensei," Yosuke whispered, face beet-red.

"I've never had to calculate something so big in our shops," Masaru said hesitantly.

Yoshiro-sensei inclined his head in acknowledgment, and the fact that all he did might as well have been a heartfelt congratulations for making it as far as they had. Though the kids probably didn't realize that.

"You may take your seats," he told them, and they scrambled to do so and flee the limelight in the process. "The rest of you, show me your answers."

Satoshi was wrong, something that clearly mortified him. Though once again, to my surprise, Yoshiro-sensei didn't rub it in. Hayato and Daigo were correct. I was too, of course, but Yoshiro-sensei spent a great deal longer examining my page.

"What is this diagram you drew, Imai-san?" he asked.

The diagram he was referring to was the lattice method, something I learned in my old world. Outside of my public school district, I encountered very few people who used it.

"It helps me stay organized when multiplying large numbers," I said simply, offering no more information. If he wanted to believe I came up with it, that would be fine by me.

He grunted. "Problem nine."

88/3

Hayato raised his hand. "How many decimal places do you want us to solve to?" he asked, and the question itself was telling. He would get it correct, but he would be out of the running soon. I, meanwhile, already had the answer.

"As many as you can," sensei replied, and Hayato got to work. In a minute, he grew visibly annoyed with himself, realizing that the answer was 29.3 repeating.

Problem ten was 631/57. I have to reiterate—I don't consider myself to be especially good at math. Especially not compared to people from my own world. But someone who was average at math by my old world's standards might as well have been Pythagoras in the elemental nations. Especially when their competitors were five-year-olds. In the time Yoshiro-sensei gave me, I solved to six decimal places, Daigo solved to three, and Hayato gracefully withdrew.

"Problem eleven," Yoshiro-sensei declared, writing on the board 7². Daigo stared at the board blankly, and I tried to keep the glee off my face as I wrote 49.

"Gomen, sensei," Daigo said. "I don't know what that means."

Yoshiro nodded, allowing him to return to his seat as he fixed his attention solely on me. "Last one standing," he noted, and I could feel the entire classroom's worth of eyes boring into my skull. "Problem twelve."

3√1728

After some prime factorization, I found the answer to be 12. Unexpectedly nice of him to use an integer. But then I realized; he was coming up with these on the fly. He needed to be able to check if I was correct. So, no question would possibly be more difficult than what Yoshiro-sensei could solve.

Thank fuck calculators weren't a thing in this world. He wouldn't be able to throw anything at me too far out of left field.

He drew a circle, and jotted down a number on the outside.

"That is the circumference," he announced. "Find the radius."

Oh, we were doing geometry now? No matter—I remembered my formulas.

Next, he drew a triangle, and I nearly had a heart attack before I recalled my earlier epiphany. Easy trig was easy. Here in the Elemental nations, cosines weren't real—they couldn't hurt me.

"Find the length of the hypotenuse," he challenged, and I did so easily.

"Very well. You've made it to the last question, Imai-san," he said. "I will not write down this next one; you will have to dissect it yourself. Are you ready?"

Oh? Was he going to give me a word problem? I nodded resolutely.

"A group of Iwa genin are sent out on a mission," he announced. "However, a day later, Command receives intelligence that the client is a fake, and intends to implicate the genin in a plot against another shinobi village, pinning the blame on Iwagakure. In response, command sends a team of chunin to pursue them. It takes half an hour to muster the team, meaning that the genin have a twenty-four and a half hour lead on them. The team of genin is estimated to travel at a rate of thirty-five miles per hour. The chunin are estimated to run at forty miles per hour. How long will it take the chunin to intercept the genin team?"

"Am I to assume both the genin and chunin teams will continue to run without stopping, even for the night?" I asked, mind whirling as I wrote down the necessary information.

"Yes."

"Cool," I murmured, realizing belatedly that it was a weird thing for someone in this universe to respond with. What was important here? I wrote down all the numbers, but it took me a second to parse out their significance. Soon, I realized the twenty-four and a half hours part was a misdirect; the twenty-four hours factored into the initial distance difference, not the time frame. Thirty-five mph equaled a starting distance difference of eight-hundred and forty. Then I factor in the additional half hour and start solving for time.

After several agonizing minutes, I found what I was pretty sure was the correct answer.

"171.5 hours," I told him. That was over seven days straight; those genin were toast. Iwa better prepare for another war.

"Correct," he said simply. "Please return to your seat."

There was a scattered murmuring around me, and I pretended to ignore it as I made my way back to the far side of the classroom.

"Chinen-san, Go-san and Ishii-san," he said, the three boys jerking up straight as their names were called. "You are excused from this class for this semester and the next." The murmurs returned with full force. "Doi-san, you are excused from the next four semesters. Hirose-san, you are excused from five. And you, Imai-san, are excused from this class for the duration of your time in the Academy. I have nothing to teach you on the subject, though I suggest you keep in mind that questions of similar difficulty will be on the final exam."

No math class? Ever again? I could have squealed. Instead, I simply nodded.

"For those of you who tested out, know that you do not have a free period to slack off," he announced, cutting through the ensuing chatter. "You will each submit a proposal to me of how you would like to spend your time. If you cannot think of anything, I will assign you something."

He looked back up at the clock. "That will have to wait. This class is over; prepare for your next."

- - - { ワナビー } - - -

When I returned home for the day, I was ecstatic and relieved to find Kazuhiro waiting for me. I had been extremely worried; the fact that he specifically was summoned, despite not having a highly demanded specialization, made me think he might not come back alive. That, perhaps, he was being punished in some way. But he was back, and he looked…happy? Like, actually happy.

"Tadaima!" I sang, wrapping my god-brother's leg in a hug.

"Hello, imouto," he greeted softly. "How is the academy treating you?"

"It's fine," I chirped. "Boring sometimes, painful other times. But I tested out of math, so hopefully it will be a bit less boring starting tomorrow."

"You…tested out of math?" He asked slowly. "What does that mean?"

"Yoshiro-sensei gave me a test today," I explained. "Me and some other kids, but I did the best by far. He told me I already knew the entire mathematics curriculum for the academy, all semesters. So he's not making me sit through all of his boring lectures! I can do independent study instead."

Kazuhiro looked dumbstruck. "...I completely failed the math portion of the academy test."

Ah. "Well, it's not like math is all that important to a ninja," I said to make him feel a bit better. "You're a chunin, and you get along just fine without it, right?"

He chuckled. "I suppose we can't all be as smart as you, Kasaiki-chan. If we were, the world would probably be a much more dangerous place."

That one throwaway line neatly summed up one of the key differences between my original world and my current one. There, knowledge was to be pursued in order to better the lives of everyone around us (theoretically). Here, knowledge was to be pursued for the sake of violence, destruction and military supremacy.

"Enough about that," I said. "How was your mission? And why were you summoned for it?"

The smile returned to his face. "It seems like your aniki impressed a couple important people. They think I have what it takes to be a jonin…kinda. I don't have the power yet, but hopefully that will change. They're going to put me in a special program to help get me there."

My eyes widened. "Really? That's awesome! Omedeto; you deserve it!"

He really did. Kazuhiro trained a lot, and he cared a lot. His dedication to self-improvement was on par with my own, though he probably didn't have as clear a vision of how exactly he should go about doing so as I did. And if there was one thing I knew, it was that promotion didn't come easy in Iwa. If he got on command's radar, there must have been a hell of a reason.

His smile dimmed, somewhat. "Thank you, Kasaiki-chan. It means a lot to hear you say that. I'm going to be taken off the roster for a bit. Not a bit, actually; a pretty long time. But the time I get to spend with you will likely still be limited. And, in a couple months, I'll be undergoing a…surgery. They called it experimental, and we're not really sure what will happen to me."

Fuck. They were going to Orochimaruize him, weren't they? Body modifications were sketchy as hell, and the fact that it was Iwa performing them, and not medically-advanced Konoha, did not fill me with confidence.

"Do you know what they're going to do?" I asked, mouth dry.

"No," he said. "They're not going to tell me. For security's sake. Even if they're successful, they'll probably only tell me enough to be able to utilize my new abilities competently."

A bit shakily, I grabbed his hand and squeezed. "Thank you for telling me."

The reply seemed to shock him. "You…you're not mad? You're not going to tell me not to go through with it?"

I sighed, the breath hitching in my throat. "What good would that do? Nii-san, you want this. I know you do. You'd regret it, if you didn't take this chance."

That was true, but there was a lot more to it than that. If our circumstances were different, I might have cried or pleaded. I might have guilted him into withdrawing, assuming he had the option. But I knew that, in a few years time, the Third Shinobi War would begin. Kazuhiro would be sent to the front lines, and, as he was now, he wasn't strong enough. He might not have what it takes to survive. So it wasn't like he was safe at the moment, not really. He could either take a risk now that would improve his chances later on, or he could not take that risk, but incur a much bleaker chance in the future.

"Thank you for your understanding, imouto," he said, voice thick with emotion. "You're such a smart and compassionate girl."

I ducked my head, feeling like a fraud, and pulled his leg into another hug so he couldn't see my face.

"I don't plan on telling Akane-obasan," he said after a while. "I don't think she would understand. Not like you."

"That's probably a good idea," I said wetly. Then, I cleared my throat. "Enough thinking about that. Let's do something to celebrate, okay? Your big promotion, and me not having to take math class anymore."

"That sounds fantastic, Kasaiki-chan," he said warmly. "How does dango sound?"

- - - { ワナビー } - - -

I needed a new project. Mapping my canals was still fun, but I'd been going at it for years now. I needed something else to keep myself sharp, something new.

I wanted that new thing to be fuinjutsu, but that was still a dead end. All I could do was practice my calligraphy, the most fundamental of the fundamentals. Akane-obasan had given me several of Atsuchi's old texts, and she was actually pretty well versed in the subject herself. She claimed that was what kickstarted her son's interest.

I didn't mind practicing it either. There was something soothing about swooping the brush around, creating elegant, looping designs with meanings hidden inside. I wasn't an artist in my past life, though I did doodle in the margins of my notebooks. Perhaps I should have been. Or perhaps this body simply had talents that my previous one lacked.

Since I couldn't do anything else to further my studies in that area, I delved back into my own chakra canals. If I could figure out my tide system, there were surely some other crazy things I could do with my internal chakra manipulation.

My eye kept on getting drawn back to my lowest stat: Shōmon, the Gate of Pain. This was the most ambiguous of all the gates, and none of my texts could shed any light upon the subject. They referred to bloodline users a lot, but for those of us without them, what was its purpose?

The answer was easy enough to find, but nearly impossible for me to understand. The Gate of Pain held a person's chakra identity. But what was a chakra identity? Elemental affinity was one aspect of it, I knew, but what were the others?

"Nii-san," I asked on our way home from a nice dessert. I might not be able to have him as a resource for much longer, so I should ask my questions while I still could. He couldn't answer most of them, but whenever he was able, he attempted to find the answers and get back to me. "What is an elemental affinity?"

"Most shinobi have a natural predilection towards one element or another," he said slowly. "Which one depends on your parents, or sometimes more distant ancestors. Before people started moving around, their affinities were reflected by where they were from. For example, people who once lived in Iwa always had Earth affinities. It's the same across the elemental nations."

I knew this, of course. "Is that all it does?" I asked. "Makes some jutsu easier to use than the others?"

"It makes some jutsu more difficult as well," he said. "If they oppose each other in the Elemental Advantage Wheel. Though some people with bloodlines hold affinities for conflicting elements." He shot me a look. "I get the sense that's not the answer you're looking for."

"Sorry, nii-san. I guess I don't know what I want to know. I just feel like there's something else to it, from some of the things I've read in my medical texts." I looked back up at him, squinting. "What does it mean for you to have a strong affinity? Just that your predilection for said affinity is more powerful? And wouldn't that be a bad thing?"

If that was the case, a stronger affinity wouldn't be helpful; it would only make it harder to use non-aligned elemental jutsu. Or perhaps all non-aligned jutsu at all, if an element had the tendency to creep into all chakra use.

"People don't typically view it that way," Kazuhiro said. "Those with strong affinities can use jutsu of their element with less of a chakra drain, and those jutsu are often more powerful too."

Okay, I've heard that theory before in fanfics, maybe even in canon. But now that I was in this world, and I knew the rules (perhaps better than most natives even), I realized that was complete bullshit.

"Nii-san, that doesn't make any sense," I said bluntly. "A jutsu can't become more powerful without the addition of extra chakra. That power has to come somewhere. If two people light a fire with the same amount of fuel, then they're going to be the same size unless they use different types of fuel. But if that's the case, the more powerful fuel must run out more quickly as well. But you said it takes them less chakra."

Kazuhiro was silent for a moment. "You know," he finally said, "when you say it like that…yeah, that doesn't make any sense."

I snorted at the confusion in his voice, and he gave me a side eye.

"You're going to become obsessed with this for the next couple weeks, aren't you?" He asked.

"I need something to keep me busy while you're in super special training," I said blithely. But truthfully, I don't think it would take a week. Because I'm pretty sure I knew where that extra chakra was coming from. There was something I would need to figure out first, though.

"How can I tell for sure what my elemental affinity is?"

I doubted Iwa would have access to the special chakra paper, grown only in the Land of Fire.

"It's easier said than done," Kazuhiro said. "There are five E-Rank elemental jutsu. You won't have to learn all of them, hopefully, but you will have to gain moderate proficiency with some of them. You'll start with the elemental jutsu you believe yourself to possess an affinity for—probably Doton in your case, though I don't have much information on your mom's side of the family. Then you'll try to go around the Elemental Wheel. If you find one that is too difficult to learn, you'll skip it, until you've found the jutsu you simply cannot manage to use. The element that jutsu is weak to is almost always your affinity."

Huh. "So I'm not trying to figure out which jutsu is easiest?"

"Usually, that's pretty difficult to tell, since they're only E-rank jutsu. You'll probably have a hard time picking it correctly out of around three of the elements. The remaining two will be more challenging, one considerably more so than the other. Unless you have multiple affinities, which is rare, especially outside of the Bloodline clans."

I grabbed his hand like the child I was supposed to be.

"Yes, I'll show you them tonight," he said in a faux put-upon voice.

"I didn't even ask you anything yet," I protested.

"You only act like a kid when you're about to ask me for something," he deadpanned.

Ah. I probably should have been more subtle with my manipulations.

"I think you'll be a great jonin, nii-san," I attempted. Not that it took a deductive genius to notice what Kazuhiro had.

"Thanks," he said dryly, before he broke into a more sincere smile. "I think you'll make an even better one, some day."

- - - { ワナビー } - - -

AN: I don't know math. If that last word problem was wrong in some way (wouldn't be surprised even after all the time I spent coming up with it), please politely look in the other direction. That took me so. Fucking. Long.

Thank Y'all for the continued support! Each new follower/favorite really makes my day.

Can't wait for you to see all the plans I have cooking, with Kazuhiro and the elemental affinities. See you next week!