Naoki's legs still ached from yesterday's run through the forest when Tsunade pointed him toward the oldest oak in the clearing and told him to climb it. Not around it. Up it.
He looked at the trunk, then at her, waiting for the rest of the instruction. There wasn't one.
"Chakra to your feet," Shizune said, crouching to tighten the strap on his sandal before he could argue his way out of it. "Enough to hold, not enough to crack the bark. You'll feel the difference the first time you get it wrong."
He got it wrong immediately. His foot slid sideways the moment he pushed off, and he caught himself against the trunk with both hands, bark biting into his palms.
Tsunade had already climbed up to the first branch without visibly trying, and sat there swinging one leg, watching him fail with an expression that wasn't quite sympathy. "You're thinking too hard about it. Chakra doesn't like being watched that closely — you're basically pinching it."
"That's not a real instruction."
"It's the only one you're getting." She smirked down at him. "Figure out what pinching means."
It took him the better part of the morning, but somewhere around his twentieth attempt, something in his focus loosened rather than tightened, and his foot held. Three steps. Five. By the time the sun had climbed high enough to burn off the last of the dew, he'd made it to Tsunade's branch, breathing hard, grinning like he'd won something.
"There it is," she said, and left it at that, which from her counted as high praise.
Water proved to be a different animal entirely. The stream near the training ground didn't hold a mistake the way the tree bark had — it swallowed his feet the second his focus wavered, and it wavered constantly for the first week. He went in more times than he could count, sometimes from his own miscalculation, occasionally from a well-timed shove.
"A shinobi's gotta expect the unexpected," Tsunade said, entirely unrepentant, the first time she dunked him with nothing more than a pebble skipped at the right angle.
"You could just tell me that instead of drowning me."
"Where's the lesson in that?"
Shizune, at least, offered him something more useful than getting laughed at from the bank. "You're bracing like the water's solid ground. It isn't — it moves, so you have to move with it. Adjust as it shifts instead of fighting to stay still."
That one stuck. By the second week he'd stopped fighting the water's small currents and started reading them instead, the way you'd read a person's footwork before a strike, and the dunkings grew steadily rarer. By the third week he wasn't reading the current at all anymore — his feet adjusted to it on their own, without him having to think about it, the same way he'd never had to think about walking on solid ground. He could do everything on the water's surface that he could do on land.
"You're getting good at seeing it coming," Tsunade admitted one morning, arms crossed, after he sidestepped a current she'd thrown without even glancing over.
"I learn fast."
"Everyone learns fast right up until they get cocky." But there wasn't much bite in it, and she was almost smiling.
It was a week after that, mist still low over the water and the grass cold enough to leave damp patches on his knees, that Tsunade called him and Shizune over and sat down across from him instead of standing the way she usually did. That, more than anything, told him something had changed.
"You've earned the next step," she said. "Faster than I expected, if I'm honest."
Naoki straightened. "What's the next step?"
"A jutsu that belonged to your grandfather. The Nidaime." Something in her voice had gone careful, deliberate, in a way it usually wasn't with him. "It makes physical clones of you — not illusions. Real copies, carrying a share of your chakra. Whatever they learn, whatever happens to them, comes back to you when they disperse."
"So I could train three things at once instead of one."
"That's the appeal, yes." Tsunade held his gaze. "It's also why it's normally kept for Jonin. Splitting your chakra like that costs you, every single clone. Push it further than your body can spare, and it's not tiredness you're risking — it's collapse. I've seen shinobi twice your age misjudge that and pay for it."
Naoki opened his mouth, and Tsunade cut him off before he could get a word out.
"I know what you're about to say. Yes, your reserves are bigger than most Jonin's. No, that doesn't mean you get to be reckless with them. We start at four clones. Not five because you're feeling good that day. Four."
He nodded, and for once didn't argue the number.
Shizune ran him through the hand sign, slow, twice through before she stepped back to let him try it himself.
Nothing happened the first time — no smoke, no second Naoki, just the flat, familiar sting of wasted effort.
"You're pouring everything into one clone and starving it out," Tsunade said. "Split it evenly. Two cups, not one overfilled and one empty."
He tried again. And again. On the fourth attempt a thin curl of smoke rose beside him, and there stood a second Naoki, wearing the exact same startled grin Naoki could feel stretched across his own face.
"There's one," Tsunade said. "Now do it three more times without falling over."
His legs already ached from the morning's water walking, and by the time three more clones stood around him, his hands had a fine tremor he couldn't quite hide, sweat cooling fast in the morning air.
"Good," Tsunade said, studying all four with a critical eye. "Two of you go with me for nature transformation. Two go with Shizune for tool work." She tapped him lightly on the forehead. "You stay right here and hold the thread connecting to all four. That's your job now — not falling over the moment it gets difficult."
"That's the boring part," Naoki muttered.
"That's the part that decides whether you can use this jutsu at all in a real fight." She was already turning away. "Sit. Focus. Don't let go of a single one."