Disclaimer: Naruto belongs to other people. Not mine. (but writing ickle Kakashi is my guilty pleasure)
Notes: Entirely the fault and brain child of Hey-Diddle-Diddle, who asked me the question in the first place. Credit and dedication go to her for being kind enough to let me write it up.
Thanks to everyone who's already given such warm comments and concrit on this XD
A few months after Kakashi'd graduated from the pre-Gennin Academy, back when he was very small, he'd overheard Sensei talking to another Jounin – a white haired old man with a strange leer, and a pony tail, like Kakashi's father. The conversation he'd walked in on had seemed very grown-up, and Kakashi had been a little afraid of being caught eaves-dropping, instead choosing to hide himself behind a small chakra mask as Sensei had shown him weeks before.
"You're insane." He could see Sensei's 'stern look' – a peculiar pinching of the brows, his mouth a dissatisfied line – and felt a peculiar glee that someone else was displeasing his Sensei enough to receive those looks. "Jiraiya-sensei, you really need help."
"Listen Brat," Jiraiya grinned toothily; a conspiratorial smile that coaxed Kakashi into listening very carefully. If he was caught, after all, he'd be safer with blackmail material than without it. "Just consider it: If bread always lands butter side down, and cats always land on their feet…"
Sensei just laughed, "Jiraiya-sama, please don't finish that sentence!"
Sama? This old man? Kakashi watched the white haired lecher wave a finger in the air, the action drawing Kakashi's attention like a student to a teacher, words to a page. A moth of potential to a lecherous flame. "…What happens when you tie a piece of bread - butter-side up - to a cat's back?"
Kakashi might've been a genius, but he didn't know the answer.
Several weeks since overhearing the conversation between his Sensei and the white-haired shinobi and the question still bugged the young Gennin. Ate steadily away at his easily influenced mind.
Logically, thought Kakashi - utilising the brilliance that had served him so well in his training so far - a fair test would be one that put both a cat and a slice of buttered bread at terminal velocity, otherwise it was a given that the cat's senses of self-preservation, balance and heavier weight load would win out. Kakashi figured a cat from a ninja village would be at more of an advantage than a slice of ninja bread – it didn't have a spine to twist with, after all – but the real trick would be to work out just how far a drop would let them both reach terminal velocity.
Kakashi got to work.
It turned out that he was too short – just dropping the writhing animal didn't work, and he seemed to always end up wiping most of the butter on his shirt in his attempts to avoid getting mauled by an unhappy cat. It was difficult to hold a full sized cat, but a kitten probably wouldn't make it a fair test. After all, how would a baby kitten understand terminal velocity?
Trees didn't work either. Sensei refused to teach him chakra-aided walking so early on in his training, no matter how Kakashi used his many secret weapons. Sensei seemed to immune to both Puppy Eyes and Blubbering with a Slice of Wailing, and that just wasn't fair. Either way, the many branched trees that Kakashi could safely climb were difficult to do so holding a struggling breaded cat; and the trees he had managed to clamber up had far too many branches to get a clean drop. Kakashi hadn't really expected cats to be quite so good at climbing trees, but at least he now knew those vicious little claws were good for something. Stupid cats.
He'd had a bit more luck with one of the later experiments - sending Maito Gai to the top of a pylon was a stroke of genius, and meant he could easily record the results from the ground below. Unfortunately Gai – being a five year old child – had the mentality of one; and quite despite all his loud announcements of surpassing Kakashi, he still preferred to chuck the cat to the ground rather than just let it drop.
Eventually, Kakashi came up with a brilliant idea, and skipped out on his afternoon lesson with Sensei to better facilitate the brain wave. (After all, Sensei always said a ninja should be spontaneous in battle, and this was practically battle, right?) Kakashi swiped a more timid looking cat from near the Inuzuka compound, figuring that he was doing the poor creature a favour anyway, so it should obviously be happy to play Kakashi's little game. He was by now heartily sick (and a little afraid) of the enormous moggy he'd been 'playing with' for the last few experiments.
Kakashi readied the experiment – carefully winding shuriken wiring in place around the cat's torso, ensuring the bread was tight and secure again the animal's back, clearing the quickest path by which to haul arse between the drop point and the results pad (a slightly lopsided chalk 'X' scrawled on the dusty ground, far below). Finally, he stood at the edge of the cliff face of the Hokage's Monument, holding the cat out at arms length carefully so as not to make it freak out and scratch his arms. He steadied his footing a little more, before starting the mental countdown.
"Dammit Kakashi, not again!" Sensei's voice travelled across the cliff top, and Kakashi squawked as he automatically pulled the experiment – the cat – into his body and tucked it safely behind his back as he turned. "That animal's nearly bigger than you, brat, don't try and hide it from me."
Kakashi let go off the cat, flinching as it wound itself around his ankles, butter smearing across the wraps on his calves. He tried to kick it gently away. Stupid cats. Sensei towered above him, hands on his hips and he looked down at the Gennin, brows pinching together, his mouth a twitching line.
"It's a 'speriment." Kakashi pouted, hating the whistling lisp caused by a missing front tooth. He sounded like a baby, and was infinitely glad no one could see the gap behind his mask. "I wanted to know!"
"Kakashi-kun," Sensei said, kneeling to a crouch and smiling warmly at the young shinobi, thankfully ignoring the frustrated shifting of Kakashi's leg as the large black cat wound lovingly - persistently - around the boy's feet. "We can't mistreat other people's pets like that. We're shinobi, you see? It's our duty to protect this village, and everything in it. Including the cats, ok?"
"Yes Sensei." Kakashi muttered mournfully as his teacher ruffled his erratic hair. "M'sorry."
"S'alright kid. Now, shall we go and train?"
Kakashi looked up happily, eyes curving atop his mask. He gave one last kick to the affectionate cat and started towards the easiest path, only pausing when the Yellow Flash didn't follow.
Watching the screeching cat tumble from the enormous height of the cliff with a bit of bread tied to its back, Konoha's future Yondaime could only wonder vaguely... what side would it land on?