Disclaimer: I do not own Naruto or any characters from that manga. Masashi Kishimoto is the dude with it all.

WARNING LABEL: Use of overused kakasaku plot devices, drinking, snogging, flirtation and general crack situations will ensue. Hope you like. This fic is not to be taken seriously.

A Lesson in Chemistry

Chapter 1 - The Science of Touch

"I suck," Sakura groaned from her prostrate position. She lay prone and flat against the canvas ring reserved for sparring matches and ninja bouts of all kinds. Funny thing, she had never really felt how hard the floor of it was…until now. Judging by the impact of her head, she'd say it had no give at all.

Tonight, Haruno Sakura was the doormat. Tonight, she got her ass handed to her on a silver platter by someone approximately half her age.

Rubbing her jaw lightly, she looked at the young Chuunin who was practically posturing like she'd just done the greatest jutsu in the Chuunin exams. And there were many spectators - way too many spectators to ever save face.

Sakura could hear the jibes and comments now. She'd never live it down.

Turning her pounding head to the right, she spied her Shishou, Tsunade, looking less than congenial. Sakura could only hope that the lack of the Hokage's amusement proved that she was drunk.

"Sakura…" Tsunade spat from her table at the edge of the arena, shaking her head.

No luck. Sober.

A shadow finally blocked out the bright arena lights above her and Sakura looked up to see Uzumaki Naruto. His bright blond hair looked like a golden halo perfectly framing his disgusted look. An angry cherub, if you will.

His eyes roved over her outstretched arms, splayed legs, and the shoulder length pink hair matted to the sweaty flooring.

He was clucking his tongue in disgust. "Sakura-chan….you suck."

Sucking in a little, Sakura managed to dislodge the tooth that had wiggled its painful self loose and she spat it out onto the mat in a perfect blood-trailed arc.

"Ew, Sakura. Disgusting."

"Could you get that for me, Naruto," Sakura said weakly as she closed her eyes.

It was confirmed. She sucked.

Even the idiot knew it.

Being a ninja isn't always easy. There are rules to memorize, comprehend and obey at all times. Protecting comrades and earning money in perilous missions were the pursuits and pride of all Shinobi. But sometimes a ninjacould slip out of that mode that keeps them in tune with what makes them deadly. Haruno Sakura managed to blast out of that mode like a cannonball and right into a research lab for two years.

Sure, it was important work; researching medical jutsu was am upper-level job. She got to save lives instead of taking them. That was a bonus in any nin's book.

But she was now what her Shishou so vehemently and abhorrently termed as "rusty." Rusty didn't sound bad unless one's teacher said it with a scrunched up nose like she smelled something bad in the room. To Sakura's dismay, Tsunade maintained that face the entire time she spoke with her after her match. Maybe Sakura embarrassed her?

"Sakura, I've noticed that you've gotten a little…rrrruuuusssstyyy."

Damn it. Did she have to drag it out like that?

Funny enough, Sakura previously felt that with all her antics, Tsunade didn't have the ability to be embarrassed. Sakura had been embarrassed for her many times and came to the conclusion that the woman felt no shame after she walked around Konoha with a mission paper stuck to her forehead and toilet paper dragging behind her shoe for two hours one morning.

Sakura was twenty-one and more capable and intelligent than many of her fellow ninja. She was just…out of practice. That sounded so much nicer than rusty.

But if Tsunade was embarrassed of her, the hit must have really looked bad, like- all-time-ninja-hall-of-failure–bad.

Flying headfirst into the floor after a girl half her size connects her just right might look a little pathetic from a ninja's standpoint. Ok, it would look horrible, but who was Sakura to begrudge some up-and-comer from getting a lucky hit?

Yeah, that's what it was.

"Shishou, it was just a lucky hit."

"Rusty, Sakura. Ruuuusssty."

Damn it.

Tsunade sat at her desk growling at the morning sun, which ignored the pleas of her hangover to go down. She sat half-slumped on her arm, keeping a wary eye on the mission reports under her tired eyes. The ugly stack of papers was follow-up from completed missions and she was starting to see a disturbing trend.

Every other A-ranked, unranked, and S-class mission seemed to be signed off as completed by a smiley face with a scar over one eye.

"Shizune? Why is Kakashi taking all the dangerous missions? Is he saving up for something? Getting married? Trying to get killed?"

"Kakashi…married," Shizune snorted into her coffee. Composing herself quickly, she straightened her outfit and added quietly, "I think he's trying to do his duty to the fullest, ma'am."

"Well, we can't have him hogging all the high priced missions. And we can't let him get burned out from constant stressful duties. He needs a break. Remember Hyuuga Neji and the shower incident? He said it was mission stress. We already know Kakashi has an addiction to smut. We don't want that going awry, do we? He needs an easy mission."

"Agreed, Tsunade-sama. But what sort of mission do you have in mind?"

Tsunade tapped her forehead with one long fingernail. Shizune could almost see the smoke as the wheels started to turn. Tsunade finally grinned.

"Well, he used to teach. I have someone in need of some help. Someone…rusty."

Shizune rolled her eyes. Sakura wasn't rusty; she just seemed to not be concentrating that day. The young woman who knocked her down got in a good shot and Sakura never used her chakra in hand-to-hand spars. She could kill someone. But Tsunade saw things as Tsunade saw things and Kakashi and Sakura would have to bow to her wisdom for a little while.

"Shizune, have Kakashi here at 2:00 for briefing. Have Sakura here at 3:00."

Shizune's eyebrows rose as she watched Tsunade begin manically searching through books piled behind her desk. Whatever she had planned was not going to be pretty.

Hatake Kakashi sat comfortably in the wooden chair across from the Hokage's desk running his fingers along the spine of the Icha Icha Paradise manga he held tightly. The desperate tickle to open it was growing so much so that Tsunade's words were getting lost from her mouth to his ears. Mission briefings by the Sannin were always so droning; it was hard to stay focused.

When a pause in her diatribe ensued, Kakashi replied just because he figured it was his turn. "Yes, addicted…I mean…rusty…yes Ma'am," he mumbled as he lovingly rubbed the cover of the orange book.

"Did you hear a word I said, Hatake?" Tsunade eyed him noticing the glazed look in that one eye.

"Every single one, Hokage-sama," he said so nonchalantly that she had to believe him.

"Alright, Kakashi. You're dismissed. Pick up your student at 4:00 at the main gate. But remember to keep that little fact about teaching her secret. Understand?"

"Of course, Hokage-sama," Kakashi responded mechanically. He pushed up from the chair and flipped open the dog-eared and well-read pages of his favorite volume. Wandering out the open door Shizune held, he was already engrossed in the budding romance (among other dirty things) of the main characters within seconds.

The large wooden door snapped shut loudly behind him, pulling him back to reality.


Sakura sat sheepishly in the same chair Kakashi had occupied an hour before. Sighing deeply, she prepared herself for the rusty chat again. But much to Sakura's great relief, Tsunade appeared to have something else on her mind when their conversation actually began.

The Hokage pulled a scroll from the top drawer of her desk and held it out for Sakura.

"Sakura, I have a mission to send you on. This scroll is to be delivered to a contact in Sand in a few days time. I have a second scroll with the mission details. You'll be accompanying Jounin Hatake."

"Hatake Kakashi? I didn't think he did anything but solo S-class missions. Is this an S-class?" Sakura's voice revealed some excitement.

"Erm…no, no, not quite that extreme. But it is important. Kakashi has been overextending himself on the higher ranked missions and I want him to take it a little easier. I think he misses your team so I thought it would be nice to reacquaint you two. Naruto and Sasuke are busy with ANBU right now, so I think it would be nice for you to….uh…take one for the team." Tsunade eyed Shizune who had her face turned away and her hand in her mouth to stifle the snorts.

Sakura creased her brow in suspicion but figured anything was better than hanging around the lab and waiting for Tsunade to insist she begin sparring with Gai for practice.

"Well, I guess it would be nice to have Kakashi…"

"Yes, it would." Tsunade ignored her and continued. "Okay, take the scroll and meet him at the front gate at 4:00 today. Oh, and if Kakashi tries to…you know… mentor you, just remember that he probably misses it and bear with him. You know, go along with anything he tries to teach you."

Sakura bit her tongue and fought rolling her eyes. Hatake Kakashi never entertained the idea of teaching them after he washed his hands of them at 12. To think he would try to take up a teacher role – unprompted – made Sakura almost want to laugh…almost.

Right now, the thought of tossing the scroll at the diamond on Tsunade's forehead was almost overwhelming.

Shizune came over quickly and wished Sakura good luck while taking the opportunity to usher her to the door. Sakura noticed the bite mark on Shizune's right hand, just as Shizune noticed the throbbing vein on Sakura's forehead.

They nodded in understanding and Sakura left, two scrolls in her clenched fists.

Four o'clock (or more accurately five o'clock) at the main gate provided a small bit of entertainment for Sakura. It seemed that the border guards were overly bored so they made continuous attempts to think of the best pick-up line to try on her. Sakura laughed appropriately, and then turned around, poking her uvula in hopes of vomiting.

"I'm going to kill you, Hatake," she grumbled softly, glancing at the clock in the gate office above the grinning male faces as it reached 5:16.

Wandering slowly, as there was never a need to rush for Kakashi, Sakura grabbed a snack of dango on the way to his apartment. Finally approaching his meager building, she sat on the curb across the street and waited. If there was one thing she knew about Hatake Kakashi, it was that he never rushed.

Tucking her sandaled feet against the curb and putting her knees together, she placed the box of sweets on her lap. With a sigh of resignation, she lifted the first stick of dango to her mouth.

Just as the first bite went down her throat, the discernable pop of chakra announced two people behind her. She didn't have to turn to see who it was.

"Here she is," Naruto's happy voice cut through the silent enjoyment of her treat. "Serendipity," he added looking at the full box on her lap.

"What are you doing here?" Sakura sighed, smacking the hand reaching over her shoulder. She looked up to see Naruto and Sasuke standing behind her, both smirking and enjoying the fact that she was back at square one while they were able to cross their arms over ANBU vests.

"Just passing by. We're heading to an away mission for a month. We were going to come and let you know we'd be gone. What are you doing?" Sasuke said evenly as he took a seat on one side of Sakura. Naruto sat on the other and before she knew it, a stick of dango was in his hand.

"Mission…at four o'clock. How did you find me here?" Sakura shook her head and tried not to look too exasperated.

"We heard you were heading on a mission with Kakashi. I just ran into Shizune at the Hokage Tower. From there it was easy. Hatake Kakashi – always late. Haruno Sakura – impatient. We figured you'd just come here and wait." Naruto smiled happily, so proud of his successful deductive reasoning.

Sakura couldn't think of a way to rebut that. She was impatient, though better than she was in her teens. And yes, as seldom as they had seen him in the past few years, Hatake Kakashi was still perpetually and annoyingly late.

"Can I have a dango, Sakura?" Naruto asked, already reaching into the box again.

Sakura sighed and dropped the box into his hands. Naruto made a small noise of appreciation between bites.

"Hm, what's this?" a familiar bored voice asked from the front step of the apartment building across from the trio. Sakura looked up to see Kakashi sitting on the bottom stair, arms balanced on knees, and that familiar orange book dangling in his hand. A fair size pack sat beside him and he looked as bored and unaffected as ever.

Simultaneously, Sakura and Naruto mumbled, "You're late."

Back at the Konoha gates, Kakashi seemed to virtually ignore them as he stared out at the forest beyond the large doors. Naruto, Sasuke, and Sakura seemed to be in deep conversation about ANBU and it interested him in no way, shape, or form. Been there, done that crossed his mind, and he sighed quietly.

As he waited for the conversation to end or at least pause, he spied some of the younger Chuunin who guarded the gate wandering closer to get involved.

Kakashi cleared his throat.

Sakura looked up at him. She knew that sound. It was the sound of 'time to go' or 'am I interrupting?' or 'that was amusing but I won't openly laugh at you so I'll camouflage it as a cough.'

"Kakashi-senpai? Do you need some water?" she said in a honeyed tone.

Kakashi wasn't oblivious to her sweet sarcasm. But the last string of his patience was stretching out. "Time to go."

Ah, that throat-clear. "Alright," she said cooperatively and nodded to Naruto and Sasuke.

Taking a step, Sakura felt her arm grasped by strong fingers. "So Sakura? You are all alone with Kakashi on this mission." Naruto drew close but didn't manage to keep his voice down.


"So…try to get a look at his face if you can."

"Are you kidding?"

"No, just try. We haven't seen it. I'm still curious." Naruto nudged Sasuke who looked thoroughly embarrassed to be within earshot of this conversation…as was Kakashi.

"I'd have a better chance of seeing his ass, Naruto," Sakura sighed, getting impatient to leave.

"Naw, we've seen that already. Just his face."

Sakura's eyes widened for several reasons. The first reason being Naruto's persistence in something they gave up on as children; the second being that Naruto had seen Kakashi's ass. Sakura had never contemplated what Kakashi's ass might look like before. It had the potential to become the sort of annoyingly disgusting idea that gets trapped in the brain to become a nightmare when finally getting to sleep.

Spinning on her heel, Sakura didn't say goodbye. All her effort went into pulling the damaging last two minutes from her mind.

Their farewell calls met her ears as she wandered out behind Kakashi, but she only raised a tensehand in response.

Three hours passed slowly and not a word had been said. The cicadas seemed to have a lot to say, as had the birds, but not Hatake Kakashi. Seemed that the only thing interesting him was his book.

Small fantasies about tossing it up and pounding it into dust played in her mind on repeat, as did the reoccurring mental image of what his behind might look like – although she had to admit he did seem like he was in shape. As far as bodies went, she'd rate him a nine. She supposed walking behind someone for three hours was bound to make you look after a while, so guilt was a non-issue.

Definitely too much time to think on this mission.

All in all, the early evening was not shaping up well.

Night was starting to fall and the stars were peeking out among the tree branches overhead. Sakura tripped on a tree root and realized that her feet were getting tired.

Oh god, I am rusty.

Making an exaggerated yawn, Kakashi stretched and popped his spine before snapping his book shut. "So, Sakura. What are you now? Seventeen…eighteen?" he asked with mild curiosity while surveying the small clearing in which they had stopped. He took in the stream beside it and the heavily leafed canopy above.

"Twenty-one," Sakura responded dryly.

"Oh," Kakashi chuckled as he rubbed the back of his head. "Well I should have guessed that. I mean…I am twenty-six now."

Sakura rubbed her forehead and laughed in frustrated amusement. "That thirty-four just sounded a lot like twenty-six, Senpai. Did you want to make camp here?"

Kakashi hm'd his acceptance and Sakura could see that he was already shrugging off his pack.

At least there were some words exchanged. At least it wouldn't be complete silence. Maybe when he tried to teach her something - because of his great desperate need to teach - then there would be more conversation.

Within an hour, the fire was blazing and the sleeping bags were out. Kakashi decided to take the second shift of sentry duty and give Sakura the time to sleep in the morning. Although he'd never tell Sakura, he had slept until noon and felt he wouldn't need as much sleep as she would. When he was sensei to Team Seven, she was always the first up in the mornings, and he figured old habits died hard.

Getting comfortable, Sakura sat down on the soft green bedroll she always used and watched Kakashi tossing broken branches into the fire. He was casual and seemed rather bored with the whole thing.

Sakura finally sighed, "I'm sorry, Kakashi-senpai. I'm sure you didn't want to do this mission. This must be incredibly boring to be paired with me. I know you're used to S-class level missions."

Kakashi looked at her and she could see his eye narrow slightly. "Why would you think that?" he asked calmly as he sat back on his own bedroll.

Sakura unbuckled her leg guards from her shins and slipped off her shoes to toss them to the side. She unclipped her short medic skirt and folded it neatly beside the shin-guards. Only left in her short black shorts and red tunic, she put her bare legs in front of her and stretched her fingers to her toes.

After the crack of a few joints and a deep breath, she seemed to slump a little.

"I know that Tsunade stuck you with retraining me, Senpai."

"Retraining?" Kakashi waved that off almost too casually before he pulled his headband off and unzipped his vest. Scratching his fingers roughly through his hair, he then settled back and looked at his younger companion with both eyes.

Sakura's head dipped and she looked up at him with the same look she normally had when punching something to pieces. It was not unfamiliar to Kakashi. He'd seen the business side of that look from under great chunks of broken ground once.

"She wants you to train me because she thinks I'm rusty. Well, I can tell you that I'm not."

"I'm certain you aren't," Kakashi added, all the while wracking his brain for a piece of his conversation with the Hokage. Perhaps Tsunade had said 'rusty' and Kakashi couldn't remember. Damn Icha Icha Paradise obsession.

"Tsunade-shishou said I was the rustiest rust that rust had ever seen. She said that I was the rustiest rust to ever rust on the rusty side of rust."

Kakashi rubbed through his hair with one hand again, making it messier than it usually was. "That seems harsh."

"Well, I'm paraphrasing. But I know that you're here to train me. I can assure you that there is no need. It was… just a lucky hit."

"Oh yeah! The ten-year-old girl. I heard about that. I'm sorry I missed it."

"She was not ten!" Sakura growled, but then forced some self-control. "She was… twelve… almost thirteen."

"I see."

"Anyway." Sakura composed herself. "I've been busy in the lab for a couple of years so I haven't had time to practice."

"Of course," Kakashi said coolly as he leaned back and crossed his feet. "What are you working on in the lab?"

Sakura seemed to brighten from her previously slumped state. Seems he hit the happy button with his question.

"Body chemistry and how our bodies react to certain stimuli. We are trying to produce certain reactions with chakra. If we can find a way to use chakra to interrogate, or even create sensations or feelings in individuals we are undercover around, then the need for hiding weapons on the body decreases. It's safer than trying to get a kunai into some spy situations."

"I see."

One pink eyebrow rose as Sakura examined his parroted answer. Sure, he wasn't excited by medical jutsu and research, but at least he could seem nominally interested out of courtesy. But then again, he was the lazy copy-nin from her preteen days. Nothing at all seemed to have changed about him.

"Let me show you," she said evenly as she pushed up from her bed and walked barefoot through the warm grass toward him. Sitting down on his bedroll beside him, she could see his eyes widen a little. She crossed her legs and pointed to his hand. "Do you mind if I…?"

Sakura reached down and grasped his wrist. She lifted his arm up and held her fingers over his bare skin between the leather glove and his rolled up sleeve.

Kakashi watched, his attention finally fully on her.

"As I press chakra into the cells of your arm, I can create a reaction along your skin."

Immediately, Kakashi felt the goose bumps prickle along his skin, making the fine hair stand up on end. A shiver went down his spine and he could actually say that his arm felt cold. Tensed fingers finally finished off the entire process and he laughed a little. "Interesting."

"It is. I've tricked your cells into thinking that it's cold. Notice the goose bumps. I didn't cause that, your body did."

Kakashi sat up from his recline. "Mind if I try?"

Sakura smiled. "You copied it, didn't you?"

"Number one thousand and one," he smirked. Putting his hand under her wrist, he gently lifted her arm and ran his fingers along her forearm. Goose flesh shivered under his fingers, and Sakura followed his touch with her eyes.

"Funny. I've got goose bumps but I don't really feel the cold."

Kakashi looked at her blankly. "I haven't used my chakra yet."

They stared at each other for a second.

The crickets seemed extremely loud all of a sudden.

"Oh," Sakura said a little too happily, "My arm is…well the skin is…very sensitive. Well, your fingers are…um…your touch is… gentle…light…" She cringed. Withdrawing her arm, she stood up and moved to her bedroll a little more quickly than confidence would let on. She plopped down and glanced at Kakashi who already had his orange book open. She closed her eyes to concentrate on the inner rant starting up.

Kakashi cleared his throat. "I've been told that before."

When her head snapped back up, he seemed to be ignoring her again but his eyes were creased with amusement.


"Well, you get the idea." She tried to appear unfazed. "Chakra stimulation is a very interesting field," shemumbled with slight indignation.

"Oh I agree. I can see a lot of possibilities for that type of chakra usage," Kakashi said from behind his book.

"You do! I know. I'm fairly excited about what could come next if we perfect the use of chakra for what we'd normally use chemicals for. I'd like to…." Sakura stopped when she saw Kakashi's creased eyes looking over his book at her.

"That isn't what you meant, is it?" she drawled.

Kakashi chuckled and refocused on reading by the firelight.

Sakura lay down on her bedroll, refusing to acknowledge his insinuation. Pervert, she thought to herself.

For a long time, she lay on her bedroll and watched the stars overhead. After about an hour, Kakashi's heavy sleeping breaths filled the small camp.

Sakura blew out a breath angrily. "Damn it. He's right. Why the hell didn't I think of that?"

A/N: thanks roark28 as always for the beta read. Thanks to icarust who bouncedthe crazy ideas for this fic with me. Thanks ladies.