"First off, lets start by pinpointing the gaps in your knowledge."

Naruto laughed nervously as Sakura snatched his bag and opened it, riffling through all his junk to pull out his biology notebook. As she flipped open the front cover, a credit-card sized image of a naked woman, posing provocatively with black censor bars covering her privates, slipped out and fluttered to the ground. Sakura froze when her eyes fell on the image.

A long, tense few seconds passed before she slowly reached for the picture, gave him a deadly glare, and ripped it violently in half before repeating the action several times until the offensive image was no more than confetti. Naruto bit his cheek to keep from protesting. He may not be that smart, but heaven help him if he opened his mouth and try to defend himself to his temperamental female friend.

Giving him one last disgusted look, Sakura glanced down at the first page of his notebook, where she'd personally stapled the course outline to ensure that he wouldn't lose it. After skimming it for a second, taking in the reading schedule and covered topics up to date, she nodded to herself.

"Alright," she said. "Can you tell me the difference between a zygote, an embryo, and a fetus?"

Naruto looked bewildered. "What?"

"I'll take that as a no. Alright, the difference between mitosis and meiosis?"

"Uh…"

"Define 'gestation'?"

"Well, you see…"

Sakura continued to ask him questions, but although she kept her face impassive and practical, Naruto could physically feel her frustration increase with every question.

"Somatic cells, stem cells, germ cells, gametes?"

"Er… kind of?"

"Okay then. What can you tell me about the women's reproductive cycle?"

"It happens every month, causing them to bleed and PMS…?" he trailed off, unsure.

She gave him a deadpan stare. "Do you even know what PMS stands for? And it's a noun, not an adjective."

"Pain in My Side with a side of bitchiness?" he tried to joke. It didn't work; in fact, it earned him a solid smack on the back of the head with his own notebook along with a scathing look and muttered words about being an insensitive ignoramus.

Sighing loudly, Sakura looked to the sky, seemingly asking for patience, before flipping through his notebook. She saw some messily written notes written haphazardly all over the pages, a lot of doodles, and a few conversations between him and Sasuke. Mainly Sasuke telling Naruto to piss off and to pay attention.

Tossing his notebook at him, Sakura rubbed her eyes with the heels of her hands and flopped back onto the grass. Naruto, feeling a little guilty, awkwardly fidgeted with the hem of his shirt as she waited for her verdict. He knew that in some way, he'd failed her. After all, she helped him all these years with his studies but he still couldn't seem to grasp something as basic as taking decent notes. And based on her quizzing, it sure appeared that he might as well not show up in class for all she knew.

He really hated feeling like he'd let her down. Really, really hated it.

After taking a deep breath, Sakura raised her arm and, without looking at him, gestured for him to hand her his notebook. Nervously, he did, and she sat up. She looked at the notebook calmly, lost in thought for a second before she faced him and smacked him upside the head again, this time harder.

"Ow! Sakura-chan, was that really necessary?"

"Yes," she said simply.

"Oh…"

"Why are you hitting the dork and what do I have to do to join in?" asked a new voice with a teasingly smug tone.

The two friends looked up and saw Sasuke walking towards them, his carried bag looking a tad bit heavier than it had at the end of classes earlier. The two of them knew that the extra weight came from the paperwork that he was required to do as part of his club. Sometimes being the vice-president of the student council sucked.

"You're out early. You usually aren't done for another half hour or so. And I'm helping Naruto with his biology," Sakura explained.

"It was a short meeting, mainly about getting this annoying paperwork done. No big news there," Sasuke said. "Why the head hits?"

"Because he's an impossible idiot who doesn't even take notes. No wonder he finds it impossible to study if he can't remember what they covered in class in the first place."

"Sakura-chan… that's a bit harsh…" Naruto whined pitifully as he rubbed the spot on the back of his head where she'd hit him.

Sasuke raised an eyebrow at him. "She found the proof of me telling you to pay attention?"

"Shut up."

"I'm not going to coddle you, Naruto," Sakura told him firmly. "Yes, what I said is harsh, and yes, I could have worded it a bit nicer. But it doesn't make it any less true. I've tried wording things nicely in the past, but since that doesn't seem to do the trick, I'll just teach you this time around in the only way I know that will make it stick for sure in your head – painful bluntness."

Naruto hung his head. He really couldn't argue with that logic. His two friends knew as well as him, and better than even his godfather who raised him, that the only way to carve concepts into his mind was to be direct – short and sweet. But with some force behind it. One or two previous teachers tried to teach him in an overly sweet way as if he was a child or mentally retarded, which only made things worse as he felt he was being talked down to more than taught.

Honestly it wasn't such a bad way to learn. It caught his attention and engaged him, weirdly enough. The only downfall in this way of learning was that it was a delicate art. Not many people could teach using that method without sounding patronizing, angry, or as if they were berating him.

Luckily, it seemed Sakura knew how to. Or at least had an inkling.

"So when are you guys going to start studying?" Sasuke asked, giving them a curious look.

"We're starting right now. From scratch," Sakura answered.

"From scratch?" both Sasuke and Naruto asked at the same time, sharing a surprised look between them.

She nodded. "It seems that, presently, Naruto doesn't have gaps in knowledge so much as just a general lack of knowledge. However," she added more gently, seeing Naruto's crestfallen look, "I know that's not quite true. I know for a fact that you have some of this information bouncing about somewhere in your head. We just have to coax it out. So I'm going to start a general review, from scratch, to help get you into the biology mindset gradually; once you get the hang of it we'll go focus on the exam material."

Naruto smiled brightly at her. She may speak so frankly at times that she may sound harsh, but she knew what she was doing. And she believed in him. That meant to him more than anything in the world.

"Alright, give me a pen and take out your textbook," she instructed him.

As he dug around his backpack to do her bidding with renewed vigor, Sasuke turned to her and gave her a bemused look. "You're starting right now?"

Accepting a dark blue pen from the blonde, she flipped open his notebook to a blank page and nodded. "The sooner the better. You can stay and be part of the review session if you like. Or you can go home. We're fine with whatever you decide, but I really want Naruto to do well, and time is of the essence."

Sasuke considered her offer for a minute. On one hand, he was tired, he was doing well in the class, and he just wanted to rest; not to mention he had the annoying club paperwork to do.

On the other hand, he really, really hated paperwork, and it wasn't due for a another few days. Plus his annoying older cousin Shisui was crashing at his place for the time being, and staying with his friends would mean one hour less he'd have to spend with the guy. Not to mention that Sakura's review sessions were damn near legendary. Not that he really needed them, but hey, she was offering and it had been years since she'd done that.

He dropped his bag beside her and sat down before flopping onto his back and rolling to his side, propping up his head with his hand on his cheek.

Getting their answer, Sakura jotted down a few notes before turning to Naruto, who'd slicked back his hair with his hand and put on some old plastic sunglasses with the lenses popped out, sitting straight and looking ready to go.

"…What are you wearing?"

Naruto blinked, taken aback, before laughing bashfully and rubbing the back of his neck self-consciously. "I, erm… haha… I wanted to seem like the role model student I promised I'd be, so… I mean, looking the part is only half the battle, right?"

Chuckling at his silly shenanigans, she removed his sunglasses carefully and set them aside before tussling his hair back into its usual wild style.

"You don't need to look like someone else, you dummy. Just be yourself. And pay attention, that's all."

"Be your attentive self," Sasuke summarized helpfully. "I'm not entirely sure that self is not a myth, but…" he trailed off, rolling quickly to his other side as Sakura aimed to kick him.

"If you stay, then you're going to be helpful and supportive, or so help me, Sasuke, I'll carry you home myself and deliver you to Shisui in a basket with a bow around your neck."

Sasuke shivered involuntarily at her threat, raising his hands in surrender. Naruto snickered at him from Sakura's other side.

"Alright, enough goofing off. Naruto, use the course guideline to find the page where the DNA and Cells chapter starts on your textbook. I know for a fact that you know your nucleic acids – those are the A, G, T, and C parts of DNA – and the basic idea of genes, so I'll skip that."

Naruto obediently did as he was told and passed the book to her. She flipped through the first couple pages before finding what she was looking for. Flipping the book around to make it visible to Naruto, she indicated at a black and white picture with a grey background and black strips of what seemed like short spaghetti bits arranged in pairs. Sasuke repositioned himself, scooting closer to Naruto in front of Sakura's crossed legs to get a better look.

"Do you know what these are?" she asked.

"Uhm… chromosomes, I think."

"You think?" Sasuke scoffed, but shut his mouth at Sakura's glare.

"Yes, they're chromosomes," she smiled at the blonde. "Now here's a question for you that I find a lot of other students don't quite know how to answer: what are chromosomes?"

"Er…" Naruto struggled to answer. He leaned closer to the textbook and looked for the bolded definition on the page, but as soon as he started reading it his mind began to fog up. Chromosomes are a thread-like structure of nucleic acids and proteins found in…

"They have something to do with DNA," he answered unsurely but determined to do his share of their deal. He knew his answer was severely lacking, but it was all he could recall.

"Good," Sakura said. She ripped out the page she'd written on, put it beside her and returned his notebook to him along with his pen. "Okay, Naruto, I want you to write either exactly what I say or how you understand what I say in your own words. Okay?" At his nod, she continued. "You're right, chromosomes have to do with DNA. They're a huge component of it, really. What I think a lot of people have a bit of a problem understanding is how the two are connected. So, in the simplest terms I can think of, I'll tell you what that relationship is. Write it down.

"Chromosomes are packages of DNA. Plain and simple. See, DNA, we know, is a long string of genes. If we were able to make it big enough to see with the naked eye, an average strand of DNA would go from one end of a footfall stadium to the other."

"Woah, seriously?" Naruto asked, looking up from his scribbling. Even Sasuke looked intrigued.

"Yep. But the problem lies in the fact that cells are tiny. If our DNA is the length of a football stadium, to fit inside a cell we'd have to somehow make it small enough, without altering it, to fit within half an inch or so." She held her fingers slightly apart to drive her point. "How in the hells is a strand of DNA supposed to fit inside a cell, never mind twenty-four pairs?"

"Good question…"

To help with her explanation, Sakura reached to her head and plucked out a long strand of her pink hair before digging into her pocket for a penny. Fishing it out, she held it in front of her for the boys to see.

"Say my hair is a DNA strand and the penny the cell it's supposed to go in. My hair doesn't fit inside the coin, does it?" she asked as she placed the single hair on top of the coin. The long ends flopped on either side of it almost comically. "Naruto, how would you think of getting my strand of hair to fit inside the coin?"

Naruto reached for the two things with a concentrated look on his face. He lifted the hair and twirled it in front of his face between his thumb and forefinger, thinking. He absentmindedly noticed that rubbing the pads of his finger together with the hair between them made a sort of knot out of the hair strand. Staring at the rumbled part of the hair, his face lit up as he got an idea.

Rubbing his fingers together in a circular motion, he watched in satisfaction as the ends of the hair strand shrunk as its length was consumed as it formed a larger knot. Grinning, he placed the little knot of hair on top of the penny. It fit perfectly, with space for a couple more on the surface.

"Nicely done," Sakura praised. "Can you tell me in words what you did?"

"I rubbed my fingers together to twist the hair into a little ball." Sasuke rolled his eyes but kept his comments to himself.

"I want you to focus on one word you said – twist. Another way to put it is that you twisted, you coiled the hair strand around itself. And by doing so it became smaller, did it not? That's why it now fits on the penny."

Taking the coin and hair from the blonde, she pocketed the penny and held up the little knot of hair between her nails. "This knot of hair – or, this coil of DNA – is a chromosome. It is DNA wrapped tightly around itself over and over again so that it is small enough to not only fit inside a cell, but also small enough to leave enough space for the other forty-seven chromosomes that must also fit inside it. One thing that you must remember about chromosomes is that it's not just the DNA made into a knot. There's also a few proteins that bind to it so it keeps its shape. Without these proteins, the chromosome will come undone. You follow?"

At the blonde's nod, Sakura smiled in satisfaction and tossed the hair away. "Tell me how you would word what I just said in a single sentence."

Naruto scratched his head with the end of his pen, with a furrow between his brows. "Chromosomes are packages of DNA… they are made of coiled DNA and proteins to help it keep its shape so the package doesn't unwind." The last sentence came out almost as if he was asking.

He looked up cautiously at her, aware that his answer was beyond simple and not all that accurate. However, instead of a scolding as he'd come to expect from most of his teachers, she smiled brightly at him.

"Good! Write that down. We'll worry about the details later; right now I just want you to have a basic understanding. Once you have that the details will be a zilch."

"Cells very small. DNA strand very big. Many DNA must fit inside cell. Answer: coil each until it shrinks enough and stuff it in," Sasuke summarized monotonously.

Sakura rolled her eyes at him but didn't kick him. He smirked at her.

When Naruto was done writing his definition, Sakura continued. "Now, you know chromosomes come in pairs, meaning in sets of two. You should know the answer as to why that is."

Naruto brightened considerably. "I do! Since there are twenty-four types of chromosomes, there are twenty-four pairs, for a total of forty-eight. So if you get half of your DNA from each parent, that means that you got twenty-four chromosomes from your mother and the other twenty-four from your father."

Sasuke looked impressed that Naruto could vocalize that much. His face said as much. Naruto, seeing his look, grinned smugly at the raven-haired boy, who shook his head at him in return.

"Nicely done, Naruto," Sakura said. "I just want to clarify one thing. There aren't different types of chromosomes. They're made of the same stuff and in the same way, the only thing that differences them is how long they are. See?" she pointed back to the image on the book. She indicated to the numbers under each pair. "Chromosome pair 1 is had the longest chromosomes. Pair two is a little smaller. Pair three is smaller than that, and so on and so forth until you get to pair 23, which are the smallest. It also helps chromosomes identify their partners. See how the pairs are identical in size? It would be really weird to have mismatched pairs."

"Question!" Naruto shot his hand straight up over his head. When Sakura gave him the go-ahead, he asked, "Why are only pairs 1 through 23 the same? Why is pair 24 different, and larger than 23?"

Sakura smiled widely, pleased by his question. "Why do you think? What is the single most important pair that we've exclusively studied?"

It took a second for Naruto to file through his memories, but when he found his answer, he snapped his fingers. "The sex pair!"

Sasuke snorted as he tried to choke back his laughter. The other two ignored him.

"Go on."

"Pair 24 has the X and Y chromosomes. They determine the sex of the baby. Two X's make a baby girl, while an X and a Y make a boy."

"Excellent! Is it possible to have two Y chromosomes?"

Naruto shook his head vehemently. "Why not?" Sakura pried.

"Because women only have X chromosomes to pass onto their baby; there is no way for the child to get a second Y chromosome. The father only has one X and one Y chromosome to give, and can only give one of the two – so the baby can only get an X chromosome from the mom, and an X only, and either an X or a Y from its dad."

Sasuke looked impressed that the blonde was able to explain that much on his own, his jaw dropping slightly. Sakura clapped her hands in delight, happily reminding Naruto that she knew that he had it in him while Naruto bashfully scratched his cheek as his face flushed under her praise.

After a shaking himself out of his shock, Sasuke smiled at his friends.

They'd be alright.

I did say I'd focus on the menstrual cycle, but that doesn't mean I won't cover other things. I want to work my way up. Consequently, the three-shot I'd originally envisioned seems to be longer than I thought. Conversations in your own head never seem as long until you start writing them down, haha.