"Play is the highest form of research." ― Albert Einstein

Itachi Uchiha first notices the shift in his younger brother shortly after their father had made a passing remark on one of Sasuke's classmates during dinner (and try as he might to hide it, Itachi had noticed his brother's hands shaking in anger as he ate). First, Sasuke began returning home later and later each night. While not markedly special on its own, Itachi doesn't miss the way Sasuke's hands are skillfully bandaged, evidence of intense training. Additionally, Sasuke had requested Itachi supply him enough dango to feed his entire classroom, and then proceeded to sequester it all in his bedroom. The peculiarity of this was magnified by the fact that Sasuke detested dango and anything else sweet. However, these changes aren't major enough to warrant any worry on Itachi's part; his brother simply became more invested in his training, and perhaps he found a partner with a pension for sweets. Itachi himself is more than partial to dango, it would be hypocritical of him to raise an issue.

The changes come to a head on the third Wednesday of late and later nights, when Sasuke comes home with a detention slip and a note from his teacher requesting a conference. When Fugaku expresses his disappointment on the matter during supper, Sasuke scoffs and crosses his arms, remarkably unapologetic. This results in the young boy being sent to his bedroom without dinner, but Itachi is far more concerned with his brother's sudden attitude adjustment than his missing one meal. Sasuke has always strove for their father's approval. To dismiss Fugaku's disappointment so easily isn't something Itachi previously thought his brother capable of.

This concern is why Itachi finds himself perching on the Academy rooftops Thursday afternoon. He layers a simple area-genjutsu over himself to turn away prying eyes, and waits patiently for his brother's class to be dismissed. Itachi will discover the root of his brother's new behavior, and determine whether whoever responsible should continue to interact with Sasuke.

"Heya, 'tachi," a familiar voice cuts in over his shoulder. Itachi doesn't hesitate in snapping his fist backwards, and Shisui leans back to avoid the blow. "How violent," Shisui teases, and Itachi knows he's smiling mischievously without having to look. After a long pause in which Itachi remains stubbornly silent, Shisui sighs dramatically. "So, why are we stalking dear Sasuke-kun today?"

Itachi isn't going to turn around. "There is no we," he begins stoically, and then — because he knows Shisui doesn't care if he's welcome or not — adds, "Sasuke had detention yesterday."

Shisui chuckles. "Are you being an overprotective brother again?" He asks. Itachi decides he has no clue what Shisui is talking about, and aims another backhand blow at his cousin to deter further conversation. It misses. "You know, if you're so worried, you probably shouldn't let yourself be distracted by me," Shisui says conversationally while dodging blows. Itachi pauses in the middle of aiming a kick and glances down at the Academy doors.

Below, his brother walks outside in the tow of a tiny pink-haired girl. Surprisingly, Sasuke isn't resisting being dragged along in the slightest, which is curious because Itachi thought Sasuke was still under the impression girls had cooties. The pinkette pulls his brother out of the Academy yard, and then turns right. Itachi notes the dango skewer poking out from between her lips as she vanishes down the street, Sasuke close behind.

"Are we following them?" Shisui whispers softly, intentionally blowing air into Itachi's ear because he knows it's disturbing.

Itachi leans away, eyes narrowed on the corner the pinkette had guided his brother down. " I am," he answers finally, intentionally leaving Shisui out, before body-flickering away in a burst of leaves.

A moment later, Shisui vanishes as well.

Sasuke doesn't understand why Sakura is so determined to accomplish a seal-less body switch. Even his brother only ever bothered to master a handful of jutsu without hand-seals, and none of them were any of the simplistic Academy three. Sitting on the grass of their favorite training ground, Sasuke observes Sakura's ensuing tantrum as she fails repeatedly with amusement.

"This isn't necessary," Sasuke says, smirking as Sakura closes her eyes to concentrate again. "Even my brother doesn't body-switch seal-lessly, and he's practically a jonin ," Sasuke emphasizes his brother's power, never wasting a chance to brag about Itachi-nii. "You're just wasting our time."

Sakura rounds on him immediately, finger pointing accusingly and jade eyes narrowed. "It might be a waste for you, but for me it's not!" she snaps. "I have three jutsu to use, and the more effective I am with them, the better!" With a huff, Sakura turns her back on Sasuke and drops down into a cross-legged position, focusing on her chakra intently.

Sasuke blinks in surprise at the outburst, used to a much more easy-going Sakura. Apparently the pinkette actually has a temper. "I only know three jutsu as well," Sasuke reasons. "I just don't think seal-less jutsu are vital for next week."

"Uchiha-kun," Sakura sighs, shaking her head. "You're thinking in the short term. I'm considering the future — as a member of a clan, you have plenty of resources to learn new skills. I don't have that advantage." Sasuke is taken aback by how quickly Sakura can switch from enraged to downright solemn, but decides not to question it. Instead, he listens intently, having learned by now that it's usually best to listen when Sakura talks (and not because she punches him if he doesn't). "I may only ever learn a handful of jutsu over the course of my career, so I need to be as effective as possible with the ones I have." Sakura explains, and Sasuke frowns.

That doesn't sound right at all, even the average chunin knows more than five jutsu. Does Sakura not realize that? Sasuke tells her so, and then watches in confusion as Sakura facepalms.

"Uchiha-kun," Sakura says patiently. "Most ninja without clans don't reach chunin." Sasuke is flabbergasted by this information, but he makes sure his surprise doesn't reach his face. Sakura notices his fingers twitch in shock anyways. She laughs lightly. "Y'know Uchiha-kun, you're pretty naïve," she remarks. "It's funny."

Sasuke crosses his arms. "I'm not naïve," he protests, offended. "It's just… why can't you learn jutsu from the library? There's scrolls there," Sasuke suggests. He has a hard time imagining how someone could be entirely incapable of learning new jutsu.

Sakura sighs. "Public libraries don't carry proper jutsu beyond the Academy Three, Uchiha-kun," she answers. "It'd be dangerous to make any powerful or unique jutsu easily available." Sasuke stares at Sakura stubbornly, arms still crossed, and Sakura sighs in defeat. "Okay, fine," she says sarcastically. "I won't waste your precious time with my drilling. What do you think we should do, oh wise one ?"

"Work on the clone jutsu," Sasuke says stubbornly. "That'll be the easiest way to leave a false trail Wednesday. And we need to practice suppressing our chakra."

Sakura rolls her eyes. "Fine, fine, we'll do that," she agrees. "You focus on suppressing your signature for now, I'll tell you when I can't sense it anymore. Once you hide it for, umm…" Sakura pauses, tapping her chin thoughtfully, before grinning excitedly. "A full minute! If you can do it for a minute, we'll switch."

Sasuke huffs. "One minute is nothing," he declares cockily. "You should work on the clone jutsu while I practice so you aren't wasting time."

"Fair enough," Sakura says, smiling at him eerily. Sasuke feels a sense of deja vu; Sakura only smiles like this when she's about to rub something in his face. Lips twisting bitterly, Sasuke suppresses whatever feelings of unsurety he has and closes his eyes. He inhales deeply, concentrating on the chakra within him, and painstakingly begins curling it up inside in his chest. He doesn't realize he's stopped breathing until his body rebels. With a gasp, Sasuke's eyes snap open, and his chakra instantly unravels as well. Sakura points at him and falls back onto the grass, giggling so loudly that the birds in the nearby trees spook. Sasuke narrows his eyes at her, but doesn't say a word, returning to his exercise stoically. It wasn't the first time Sakura had laughed at him; he was learning to just ignore it.

(In the trees, Shisui muffles his laughter behind his hands. Itachi, irritated, uses his distraction to smack him out of the tree, and then returns to focusing on his brother, who is again trying to suppress his chakra. He watches the pink-haired girl - Sakura - poke Sasuke, urging the boy to breathe.

... Itachi supposes he approves, for now.)

Iruka stares at the children at his feet; his most common guests in detention. Sasuke is refusing to meet his eyes, while Sakura grins excitedly from her latest success. Both children are covered in dirt and scuff marks from their recent escape attempt, and Iruka narrows his eyes at them. He himself is breathing heavily, covered in sweat and red-faced. The duo had led him on a five hour chase around Konoha, managing to skip all but the last hour of class.

"What have we learned from this?" Iruka asks finally, foot tapping the ground impatiently.

Sasuke gives a stubborn grunt in response, and Iruka glares at him intensely. Sakura raises her hand eagerly, bouncing on her knees. "Clones are a great distraction! And we need to learn how to make solid ones!" she answers happily without waiting for Iruka's approval. (He wonders why she bothered to raise her hand at all.)

"No!" Iruka snaps, and then pauses, because that isn't quite true. "Well, yes, clones are good distractions and making solid ones would be a very useful skill for you — but that isn't what you're supposed to be learning here!"

Sakura blinks, opening her eyes unnaturally wide, and drops her head sideways like a curious canine. "What do you mean?" she asks with mock-innocence. Sasuke winces, then tries to cover it up by crossing his arms, staring a hole into the ceiling.

Iruka sees the amusement in Sakura's eyes, and his entire body tenses. He already knows that any ordinary punishment he assigns won't deter her. For Sakura, things like cleaning or training are just opportunities for fun. There is only one way Iruka can discipline Sakura: abject boredom.

"Since you asked," he begins sweetly, stepping towards the board and pulling out a piece of chalk. "I'm going to give you an in depth explanation on school policy for skipping." Sakura's mouth drops open in horror, and Iruka doesn't miss how Sasuke's eyes widen. "It should only take an hour or so, I want to make sure you don't forget." He bites out the last word, sadistic satisfaction bubbling in his stomach at the terrified expressions on his students faces. It is time for revenge.

(That evening over grading papers, Mizuki will point out that as a teacher, Iruka isn't supposed to indulge in his students' fright. They then both cackle in unison. It's because they are teachers that they feed off the fear of little brats.)

After their promised hour-long lecture on Konoha Academy rules, Sakura walks Sasuke home. The sun is setting in the distance, the entirety of Konoha bathed in red-orange light. The streets are practically empty of people, the morning markets cleaned up and most citizens having already returned home to their families. Sakura is as cheerful as usual, skipping along beside Sasuke with a wide grin, unperturbed by Iruka's punishment.

"Today's attempt went great!" she cheers. "I don't think I've ever managed to last that long before. We were this close," she holds up her pinched fingers, one eye squinted shut.

Sasuke huffs, forcefully shoving his hands into his pockets. "We got caught, that's all that matters," he says grumpily, glaring at the ground.

"No it doesn't!" Sakura disagrees immediately, jumping in front of Sasuke with her arms spread, forcing him to stop. "Progress is progress, Uchiha-kun. You can't expect to learn everything immediately, that's not how training works," she insists, pointing a finger in his face.

Normally, Sasuke would just pretend to ignore Sakura's nagging, but this time his expression darkens into something thunderous. "We failed," he repeats, slapping Sakura's hand out of the way. "That's all that matters!" He storms forward, shouldering past Sakura, who's frozen in shock. (Sakura doesn't understand, she doesn't know who Sasuke's brother is. She has never known the pain of second-best, Sasuke thinks angrily.)

"Maa, that seems mean," a new voice cuts in. Sakura and Sasuke both spin around to see a stranger with silver hair standing in the middle of the road, an orange book in his hand. Sakura habitually catalogues the hitai-ate covering his eye, the green vest, and absolute silence of his footsteps. Elite ninja, minimum chunin, she assesses.

Sasuke glares at the newcomer. "Who're you?" he demands, feathers clearly still ruffled from whatever his problem had been with Sakura.

"Isn't it polite to introduce yourself first?" The stranger asked, his only visible eye closing as he assumedly smiled.

"My name is Sakura Haruno, and this is Sasuke Uchiha," Sakura answers politely, deciding to intercede on Sasuke's behalf before the academy student could pick a fight with someone clearly stronger than either of them. Then, unable to resist, she adds, "And it's not polite to drop in on others' conversations either."

The stranger visibly scans Sakura from head to toe, then smiles again. "I never claimed to be polite," he says, tone so cheerful it almost disguises his rude hypocrisy.

Fortunately, Sakura isn't one for manners either. "Fair enough," she agrees, mentally noting his paranoia and upping his ranking from chunin. "So, jounin-san, is there something you need?" she specifies.

The stranger's gaze sharpens. "Mou, I was just curious about the two children yelling at each other in the street," he replies evasively. Sasuke grunts skeptically, crossing his arms and shifting towards Sakura defensively.

"Oh, well that's easily explained, jounin-san," Sakura says, not realizing she's already started to copy the stranger's speech patterns. "My friend and I were on a mission recently, and it didn't quite go as planned. I can't tell a nameless individual any details."

"I wasn't aware that academy students went on missions," the ninja responds amusedly.

Sakura smiles cheerfully, sliding into position beside Sasuke. The ninja is too nosy for her comfort. "Our enemy is merciless," she chirps. "Age is meaningless, he captures anyone in his way."

The ninja raises his only visible eyebrow, smug glint in his eye. "So you're the academy escapees, hm?" he says, having clearly puzzled out their identities. "Maa, you both have been sending your poor sensei into hysterics. He's been at the bar Wednesday nights almost religiously."

Drat, Sakura thinks. This guy is way better than Iruka-sensei at mind games. "That's too bad, sensei is always telling us that drinking is a bad habit for ninja," she says, shifting onto her toes. Time to get out of here. "He should try mint tea next time, it's more soothing." Sasuke's eyes flash over to Sakura's face, hearing her slip in the code word 'mint'. The two share a quick glance of agreement — they would dump the stranger and settle their differences elsewhere.

"I'll be sure to tell him next time," the stranger agrees placidly. "But yo—" Sakura tilts her head to the right, and both her and Sasuke immediately vanish in puffs of smoke, leaving potted flowers from down the street in their wake.

As soon as their feet hit the pavement in front of the flower shop, Sasuke uses his grip on Sakura to twist her into the small crack between the buildings. It's barely big enough for the two children to squirm into, and once they're tightly pressed between the brick walls, they wait silently for any sign of the ninja. After a full minute of peace, Sakura brushes her knuckles along Sasuke's wrist, and the two use their chakra to crawl up onto the roof.

"That guy was super nosy—" Sakura starts to complain once they're both out in the open, only to be cut off by hand gripping her collar. The pinkette is lifted clean into the air, and she watches the ninja from before pick up Sasuke the same way.

"Nosy, hm?" A familiar voice echoes over her shoulder, and Sakura looks up to see the same ninja holding her as well. Her eyes squirrel between the two identical men holding Sasuke and her captive. "You know, it's very, very rude to walk away while someone is speaking," the annoying ninja scolds mockingly.

Sakura narrows her eyes. "You made a solid clone," she realizes, mind instantly supplying her with possibilities. "How?"

"It's a shadow clone," the ninja surprisingly answers. "It's far beyond your current level, although you both are very good for your age. A bit arrogant to think you could escape a jounin though."

"Hah!" Sakura bursts, pointing at the ninja triumphantly. "I knew you were a jounin!" she cheers, undeterred by her imprisoned state. Sakura has had plenty of experience annoying her captors.

The ninja stares at her blankly. "Congratulations," he says dryly. Sakura opens her mouth to banter back, but Sasuke speaks first.

"The shadow clones," he says, focused on the important information. "How do you make them?"

The jounin looks between Sakura's eager expression and Sasuke's determined eyes, and then sighs. "It's like a normal clone jutsu, except the chakra is channeled outward through your feet and shadow instead of your hands," he explains. "But with your current chakra reserves, attempting the jutsu would be fatal for either of you," he warns.

Sasuke clenches his jaw at being called not good enough, even indirectly. Sakura, however, only looks more determined. "Then I'll find somebody with big enough reserves," she declares. The jounin looks them both in the eye and then shrugs. He drops Sakura and the clone holding Sasuke dispels. Both children land on their feet, and when the ninja moves to stroll away, Sakura calls out, "I thought it was rude to leave in the middle of a conversation?"

The ninja glances back at her and smiles. "Not polite, remember?" he answers, and then vanishes with a swirl of leaves. Sakura stares at the spot where he had been for several seconds, disappointed. She still hasn't gotten his name.

Sasuke grunts. "We'll need to find someone with large reserves for your idea to work," he says.

Sakura nods in agreement, ever-present smile twitching in irritation. "That annoying-ninja really was useful!" she cheers, grabbing Sasuke's wrist tightly and dragging him off the roof. Sasuke winces, Sakura's frustration obvious in her too-tight grip, but allows her to drag him all the way back to the gates of the Uchiha District. There's been enough arguing for today.

(When Kakashi vanishes, he reappears between two houses, the rooftop still in view. He looks at the two boys observing Sasuke and Sakura. "So," he starts, smiling cheekily. "They're why you've been creeping around all day, Weasel-kun."

"I'm not in uniform, please address me by name, taichou," Itachi prompts, expression deadpan. Beside him, Shisui is holding a stick and poking Itachi's shoulder repeatedly, and Kakashi wisely takes a step back when he notices Itachi's fingers twitch.

Shisui laughs, ignoring Itachi's rising temper, or perhaps stoking it. "Our dear Weasel-kun is a dedicated stalker!" he teases, and then automatically ducks when Itachi finally lashes out. Kakashi watches the two fight in amusement, and tries to forget how much Sasuke and Sakura reminded him of himself and Rin. At least, he thinks, there isn't anyone like Obito between them. That would be far too cruel.)

(In his apartment a few blocks down, Naruto Uzumaki sneezes, his massive chakra reserves spinning in and around him.)

(Kakashi would regret that thought later.)

I have also posted this story on Archive Of Our Own under the username "Bleunox". Thank you to the anonymous reviewer who pointed out I hadn't mentioned it! And to answer everyone's questions: Yes, this is a Non-Massacre AU, and it will be multi-chapter, probably 4.

I enjoy exploring the butterfly effects of different "what if" scenarios. In this case it's: What if Sakura and her Inner never split? Basically, exploring the effects of a more impulsive Sakura who actually uses her intelligence.