"Since we've identified your chakra natures, it's time for the next training."
The Land of Rain was riddled with rivers and swamps. If you couldn't fight on water like it was solid ground, you might as well paint a target on your chest.
"Tree-climbing uses fixed chakra adhesion. But water-walking…"
Fugaku took a step.
He stood motionless on the surging river as though nailed to it. Waves rippled beneath him, but his body swayed in perfect synchrony—unshakable.
"Water is fluid. It has no fixed form. You must constantly adjust the chakra output at the soles of your feet to match the flow."
He turned to both of them."This—you must master."
"Understood."
Minato studied the river's surface, his blue eyes narrowing thoughtfully.
He dipped one foot forward, feeling the subtle shifting resistance of the water beneath.
"I see… it's not about gripping—it's about support."
And then, in one smooth motion, Minato rose onto the water.
At first he wobbled slightly, like walking a tightrope—but within ten minutes, he was jogging across the surface.
"…"
Tetsu didn't even get the chance to open his notebook.
He stared at Minato, now sprinting casually across the river, then glanced toward Fugaku's unreadable expression.
So this is what a natural prodigy looks like…
"Don't look at him—look at the water!" Fugaku snapped."If you haven't got it down by sundown, you're skipping dinner."
Tetsu sighed, stepping to the edge of the river.
Surface tension… fluid dynamics… buoyancy equations…
He began constructing models in his head.
This isn't static friction like with tree-climbing. This is dynamic balance. No steady output—requires high-frequency pulsed control…
SPLASH!
Attempt one: Foot slipped. Half-submerged instantly.
"Too heavy," Fugaku commented coldly from shore.
SPLASH!
Attempt two: Overcompensated. The repulsion force launched him backward like a skipping stone.
"Too dumb."
The entire afternoon passed in this fashion—Tetsu taking impromptu river baths as he iterated on his chakra output formula.
By sunset, teeth chattering, soaked to the bone, lips tinged purple—he finally wobbled atop the water's surface.
He wasn't as smooth as Minato—far from it—but he could stand.
"Passable."
Fugaku tossed him a towel without ceremony."Rest up. We resume at dawn."
2:00 A.M. – Dead of Night.
The rain hadn't stopped. It never did. The gentle patter against the tent's canvas had become white noise.
Minato slept soundly, breath deep and even—his stamina worn down from the day's drills.
Tetsu's eyes opened.
Years of lab work in his past life had turned him into a light sleeper with unpredictable rest patterns. A sudden urge to pee drove him from his sleeping bag.
But when he glanced toward the corner—
Fugaku's cot was empty.
Neatly folded blanket. No sign of disturbance.
"Fugaku-senpai…?"
Tetsu frowned.
Meeting with Jiraiya? This late? Or maybe…
He threw on his rain poncho and stepped outside.
Guided by the dim glow of lanterns and the faint moonlight through the clouds, Tetsu didn't go toward the latrines.
Instead, his feet—almost instinctively—brought him to the training field by the riverside.
The same place they had practiced earlier.
A sudden wave of heat brushed his face.
FWOOSH—!
Cough! Cough!
From behind a boulder, a muffled cough echoed.
Tetsu crept forward and peered out.
There stood Uchiha Fugaku.
Gone was his high-collared clan uniform. He wore only a tight combat vest. And right now, he stood by the river, back turned to the camp, soaked in rain and sweat.
He was training.
"Compress… compress more…"
His voice was low and tense, filled with grit."If what that brat said is right… boost the oxygen…"
"Snake – Ram – Monkey – Boar – Horse – Tiger."
"Fire Style: Great Fireball Jutsu!"
A fireball erupted—but Fugaku abruptly inflated his cheeks, forcing the chakra to compress midstream.
The flames narrowed and flickered blue…
BOOMF!
A puff of black smoke burst in his face.
Cough! Cough! Cough!
The fire misfired, leaving a trail of soot and burnt residue across his mouth and cheek.
"Damn it… the theory should work!"
Wiping away the ash, Fugaku muttered through clenched teeth.
"Is it chakra rotation speed? Or mixing timing?"
He inhaled again, preparing another set of seals.
During the day, he'd only tried once—just enough to look curious, not desperate.
But truthfully? Tetsu's theory had been eating away at him.
If he couldn't swallow his pride to ask for help during daylight—
Then he'd master it alone, in secret.
—
"Compression isn't about brute force, senpai."
A voice called out from behind the trees.
"Who's there?!"
Fugaku's muscles tensed. A kunai appeared in his hand as he spun—
Only to find Tetsu standing calmly under the trees.
The mix of panic, embarrassment, and fury on Fugaku's face was… exquisite.
Like a student caught by his tutor sneaking in some extra homework.
"What are you doing here, senpai?"
"I was just… patrolling,"
"Right. Patrol. "Tetsu deadpanned.
"And that patrol involves breathing fire at a river?"
Tetsu stepped forward—not mocking, but calmly.
"You're on the right track, senpai. But your method is wrong."
He pointed to Fugaku's throat.
"You're using your mouth and cheeks to manually compress the chakra. That creates backflow. It can burn your throat."
Fugaku's instinct was to bark at him, tell him to go sleep.
But the analysis… made too much sense.
He fell silent.
"...So how should I do it?"
His voice dropped to a barely audible murmur.
Tetsu held back a smile.He's so tsundere.
He crouched and drew a spiral in the mud.
"Turbine pressure."
"You need to spin the chakra into a vortex in your throat. Use centrifugal force to draw in air. The combustion happens just outside your mouth, not inside."
"A vortex…"
Fugaku studied the diagram, eyes gleaming faintly.
"Don't hold it. Let it ride the spiral and release on the flow."
Fugaku nodded slowly and began again.
This time, his focus wasn't on muscle—but on chakra control.
"Fire Style: Great Fireball Jutsu!"
VMMMMM—!!
The sound resembled a jet engine whine.
A tight, coherent stream of blue flame shot out, lancing across the river and evaporating water as it went. It left a glowing, molten hole in the rock on the far shore.
No backfire. No black smoke.
Perfect.
Fugaku stared, transfixed.
He'd doubled the power—without increasing chakra use.
He lowered his hand, breathing hard, rain washing the sweat from his brow.
Then turned back.
The two stood face-to-face in the dark.
Finally, Fugaku coughed awkwardly, wiping his face.
"...This was just a side experiment. I wasn't… testing your theory or anything."
"Of course not," Tetsu nodded seriously."A true genius just happens to reach the same conclusion independently. By coincidence."
Fugaku grunted—but the corner of his mouth twitched upward.
He stepped closer and clapped Tetsu's shoulder, the force surprisingly gentle.
"Tonight's events…"
"You didn't see a thing."
Tetsu saluted, voice flat."I came out to pee. It was dark. I saw nothing."
"...Good."
Fugaku allowed himself the faintest smile.
"Go to bed. Tomorrow, we keep training."
"Understood."
Tetsu turned to leave.
Just before he vanished into the trees, a low, offhand voice called after him:
"By the way…"
"Your water-walking today wasn't entirely disgraceful."
Tetsu paused—then raised a hand behind him and waved without turning.
No reply.
But behind him, in the rain, Fugaku stood quietly for a long time. Looking out at the river now scarred by a brilliant blue flame.