The Hiten Mitsurugi Kid
Summary: Yahiko, tired of being beaten up by bullies, learns awesome martial arts skillz from a strange drifter boarding at his sister's dojo. Seriously.
Disclaimer: I own neither Rurouni Kenshin nor the Karate Kid. No money was made in the making of this fic.

It was getting late when he dragged himself to Dr Genzai's clinic.

"Tilt your head back," the doctor said, his tone mild and non-judgmental. Yahiko gritted his teeth and tipped his head back; it was not the pain or the superficial injuries that worried him, as much as the knowledge that he had to hide them from Kaoru.

His elder sister was fiercely protective. He couldn't bear the thought of telling her that a gang of bullies was making his life hell.

"Well, Yahiko," the doctor said, "I can fix your scrapes and bruises. But this is the third time this month you've come into my clinic after a fight with Gohei's boys. You have to find some way to put an end to this."

As if it was that easy.

He snuck onto the dojo's grounds over the back fence. Kaoru was growing suspicious of the number of injuries he'd sustained at school in "sporting accidents"; he would rather not try to explain the latest bruises. But his hot-tempered sister was nowhere to be seen. The bustling sounds of pots and pans and the smell of rice, fish and miso led him to the tiny kitchen where Kenshin was cooking dinner, humming under his breath.

"Oro?" Kenshin said comically, turning around – as he always did – as though he sensed Yahiko's presence even before he announced himself. "Yahiko? What have you done to your face?"

It said a lot about Kenshin that his red hair was the least strange thing about him. In the two months since he'd drifted into Tokyo and Kaoru had offered him a place at the dojo, he'd somehow become part of their lives: cooking all their meals, doing most of the housework, humming contentedly as he sat on the low veranda, enjoying the sunlight and the warmth.

And so Yahiko, who had felt alone and isolated for so long, felt comfortable enough to unburden himself to Kenshin's uncritical audience. When he was finished, Kenshin looked at him for a long while.

"I suppose you already tried to stand up to them?"

Yahiko bristled defensively. "I tried! They wiped the floor with me. And then," his breath hitched, "they laughed."

"Ah." Kenshin was silent for a time, his strange purple eyes distant and unreadable.

"How can I defeat them, Kenshin?" he prompted. "They're so much stronger than me."

"Only in body."

Yahiko snorted. "Spirit isn't worth a damn."

Kenshin shook his head. "Physical strength and aggression are ultimately empty. When you're too tired and hurt to take another step, when the odds against you seem overwhelming – that's when you need something more."

"What, like bushido?" Despite himself, Yahiko was intrigued.

"If you like. A higher purpose, something greater than yourself. Some men call it duty, or honour."

"What do you call it?"

Kenshin smiled faintly. "Once, I called it hope for a better tomorrow."

Yahiko thought this over. Kenshin was prone to such cryptic statements. "That's all very well," he said practically, "but it's not going to help me against Gohei, is it?"

The next day they caught up with him as he walked home from school. Hooting and calling to each other, Gohei and his group of bokken-wielding bullies drove him through the streets, ambushing him, dogging his heels as he tried to run. They finally cornered him at the gates of the dojo, grabbing his bag and jerking him off his feet. He shouted and swung ineffectually at them, and Gohei dumped him on the ground, laughing uproariously. His bully-boys stood behind him, blocking any avenue of escape; they pushed him back down when he tried to get to his feet, closed in on him in anticipation of the beating to come.

And that was when Yahiko saw Kenshin coming up the street towards them, carrying the groceries in a woven basket. Gohei followed his gaze, and his eyes lit with cruel, bullying delight.

He turned away from Yahiko to focus on Kenshin. "What are you looking at, you red-headed freak?" he sneered, brandishing his wooden bokken. "Stay out of this if you know what's good for you."

Calmly, still holding the basket of groceries, Kenshin held up his hands in a conciliatory gesture. "I'm very sorry," he said, "but Kaoru-dono gets very short-tempered when dinner is late. Do you mind–?"

"Kaoru-dono?" Gohei repeated, beaming with malicious glee. "Listen to yourself, man! What kind of a man plays housemaid for a woman he's not even –"

Yahiko was never quite sure what happened next. Oh, he saw the general sequence of improbable events: Kenshin seemed to slip and stumble forward, the basket of groceries flying free and crashing into Gohei; the big youth roaring in outrage and rallying his followers to rush forward and crush Kenshin. But Kenshin managed to stay just out of their way, always one step out of sync; he zigged when they zagged, staggering unpredictably and waving his hands in dismay, somehow causing them to run into each other and tangle up, their blows falling on each other rather than him. It was like provoking a swarm of bees; Gohei was bellowing angrily and waving his bokken in earnest –

And then the dojo gates swung open and Kaoru stood there, looming like the wrath of God, drawing herself up to her full height.

"What is going on here?" she demanded wrathfully, blue eyes sparking fire.

Gohei and his boys, frozen in the act, broke and fled. Kenshin stared at her for a moment, eyes wide, before he dusted himself off and began to pick up the scattered groceries. And Yahiko picked himself up off the ground and prepared to face the music.

It took Yahiko two hours after dinner to talk Kaoru out of hunting down Gohei and administering some righteous Kamiya Kasshin style justice. In the end he told her that anything she did would only make it worse for him, that he had to stand up to them himself or be forever shamed. She acquiesced with bad grace and a distrustful scowl, muttering under her breath.

Yahiko went to the dojo, feeling the cool, polished wood beneath his socked feet, taking in the atmosphere of centuries-old tradition. He wished, now, that he hadn't resented it so much after his father's death, and that he hadn't been so adamant in spurning Kaoru's repeated offers to teach him Kamiya Kasshin Ryu.

Uncertainly, he crossed to the rack of bokken on the dojo wall, lifted one out of its brackets. It was heavy, he thought, giving it an experimental swing; heavier than he'd thought, from the ease which Kaoru brandished hers. Slowly, he stepped into the middle of the floor, sank into an approximation of Kaoru's stance, and for a few glorious moments pretended that he was a great samurai, throwing aside his straw hat, killing multiple villains in the time it took for the hat to fall to ground. He swung the bokken recklessly, stepping forwards and sideways and backwards, fighting imaginary enemies –

Until the bokken was intercepted by Kenshin's cupped palms.

"Kenshin!" Yahiko stumbled back, startled. "What are you doing here?"

Kenshin looked down at the bokken now lying across his upturned palms. "Watching you. Kaoru-dono told me that you had always refused to learn kendo."

"Yeah, well, that was before Gohei and his bullies came."

For a long moment, Kenshin stared at him, his eyes far sharper than their usual amiable vacuity. "You cannot take up the sword with revenge in your heart, Yahiko."

"I'm sure as hell not turning the other cheek!" Yahiko snapped. He snatched for the bokken, but Kenshin slid smoothly away. There was an odd kind of grace to his movement, the same kind of grace that Yahiko had noticed as he eluded Gohei's bullies.

"Never, ever in haste," Kenshin said quietly, his tone very different, now, from his usual cheerfulness. "Never in anger, or reckless impulse."

"Kenshin," Yahiko breathed. "Are you –"

"The first thing you must learn," Kenshin said, snapping the bokken out to the side, a crisp sideways flick that Yahiko recognised, incredulously, as chiburi, "is that the sword is first and foremost a weapon. And kenjutsu," he continued, as Yahiko gaped at him, "is, at its most fundamental, the art of killing."