Yagami returned to the small lakeside.
As expected, Senju Tobirama truly was a genius — the jutsu he'd created was utterly unique.
Most Water Style techniques focused on impact-based damage.
But Tobirama had gone further, studying the principle of a centrifugal pump, using chakra to accelerate the spinning flow of water — generating incredible internal pressure and giving the stream an astonishing initial velocity.
Still, Yagami realized, that wasn't the true limit.
A new idea struck him. What if he used two rotating vortices — like dual centrifugal pumps — to simulate the principle of a gear pump?
In his previous life, gear pumps generated much greater pressure than centrifugal ones.
Two gears spinning in opposite directions, meshing together at high speed — the contact point formed continuous vacuums that drove intense pressure.
After forming the hand seals, Yagami gathered a small mouthful of water.
No need for excess — generate and use it as needed.
He slowly completed the next seals, shaping two distinct vortices inside his mouth.
One spun clockwise, the other counterclockwise.
Carefully, he guided them closer together.
When the two whirlpools collided, they locked like interlocking gears.
Now, not only did each vortex generate its own centrifugal pressure, but their meshing created an added compression pressure between them.
Yagami felt the water pressure in his mouth surge.
He unleashed the stream — this time, it was faster.
The jet pierced straight through the first tree and buried itself deep in the trunk of a second.
Maintaining the chakra flow, he swept the stream sideways — the Water Severing Wave carved through both trees in a single motion.
Success!
By slightly modifying Tobirama's design and applying his past-life knowledge of fluid mechanics, he'd created a far deadlier version of the jutsu.
He named it Water Style: Twin Vortex Water Severing Wave.
After over a dozen repetitions, Yagami's control grew more precise.
He aimed the technique at a boulder this time.
The spinning water jet struck the stone, slicing it cleanly in two.
Such cutting power — in real combat, this would be his sharpest blade, a water-forged sword.
For now, his exploration of the technique was complete.
What remained was time — endless refinement:
Increasing mastery, reducing chakra cost, enhancing output power.
And training his sealing speed — because hand seals weren't just gestures, they were the rhythmic flow of chakra itself.
Only by synchronizing both could one truly perform seals with speed.
He remembered that, in the original story, Fukasaku the Toad Sage had once used a similar water technique to slice through Nagato's summoned beasts.
If he could reach that level of power, it would become a truly terrifying jutsu — high velocity, wide-area cutting, devastating precision.
By the next afternoon, Yagami received his next mission, to assist with security during the Jōnin Council meeting.
It was an easy task.
After all, who would dare launch a spy attack during a gathering of over a hundred elite Jōnin?
That would be suicide.
During such meetings, ANBU were mostly there to serve as the Hokage's shadow — relaying commands, delivering scrolls, or summoning people for reports.
On the second floor of the Hokage Tower, over ninety Jōnin had assembled — those not deployed to the front lines or ANBU operations.
Yagami stood silently in a corner of the hall, performing his dull guard duty.
At the front podium sat Sarutobi Hiruzen, Shimura Danzō, and Koharu Utatane.
The head of the Jōnin Corps — Nara Kakaku, clan leader of the Nara — stood and spoke:
"Everyone here has already heard — the Hidden Sand Village has declared war on the Hidden Leaf.
The main purpose of today's council is to assign leadership for the Land of Rivers front — overall commander, deputy commander, and division captains—"
"Hold it right there!"
The sharp voice made Yagami perk up instantly.
Someone had just interrupted the Jōnin Commander mid-speech. Bold move.
But when he saw who it was, he wasn't surprised — Tsunade.
Seated in the first row, she stood up, eyes blazing.
"Before we rush to decide the Riverfront command," she said, "shouldn't we first discuss what went wrong on the Grass and Rain fronts?
Too many Leaf shinobi died there. Doesn't anyone here think we should reflect — or take responsibility?"
Her words filled the chamber with heavy silence.
All eyes turned toward the three elders on the podium.
Yagami admired Tsunade's spirit — she spoke with conviction — but he also knew it was reckless.
The elite didn't yield to passion.
Sure enough, Nara Kakaku replied smoothly:
"The losses in the Land of Grass and Land of Rain pained the village deeply.
However, according to the reports from Commander Mitokado Homura, we successfully drove out the Hidden Stone forces from Grass, and negotiations with the Daimyō have secured the Leaf exclusive rights to provide Guard Shinobi.
After the war, Konoha will receive a portion of Grass Country's mission contracts.
Sacrifice is inevitable — for the sake of the village."
His words were polished — a perfect political shield.
"For the village." That phrase alone silenced dissent.
But Tsunade wasn't one to back down.
"I proposed before that every squad should include a medical ninja," she said.
"If each team had one, the mortality rate would drop drastically.
If that's impossible, then at least double the number of medics on the front lines!
It's such a simple, obvious solution — why does the village still refuse?
I've never hesitated to sacrifice for the village, but even sacrifice has its limits.
Why can't we do something — anything — to reduce it?"
Utatane Koharu, responsible for internal affairs, was forced to respond.
"Lady Tsunade," she said carefully, "training a medical ninja takes years.
They must learn anatomy, medical theory, and healing ninjutsu.
It takes at least five years to turn a Genin into a qualified medic.
The medical theory scrolls alone could fill a wagon.
The village knows the value of medical shinobi — but the investment is immense, the timeline too long.
In wartime, it's simply impractical.
Once this Shinobi World War ends, I'll gladly hear your suggestions in full."
She didn't need to say the rest — everyone in the room understood.
Treating a single wounded soldier cost far more resources than replacing him.
It was cheaper to send new cannon fodder than save the fallen.
Genin were disposable grunts, Chūnin, expendable squad leaders.
That was how the war machine stayed "efficient."
Many clan Jōnin nodded along — they understood the logic.
But those few civilian-born Jōnin, who had fought and survived through sheer will and luck, now looked downcast.
And then—
Senju Hanaki, clan head of the Senju and director of the Konoha Hospital, rose from her seat.
"Lord Hokage," she said, "the Senju Clan still has two hundred twenty-seven active shinobi.
We are willing to dedicate our strength to the village — to serve as medical ninjas and heal the wounded.
Our clan's unique constitution and heritage mean many already know basic medical techniques.
At present, one hundred twelve of our members are trained medics.
Of the remaining one hundred fourteen, Tsunade and I are confident we can train at least fifty more within one month."
The entire hall fell silent.
Every Jōnin turned in shock toward Hanaki and Tsunade in the front row.
What were the Senju planning?
By volunteering to become medics, they were effectively withdrawing their forces from the front lines — removing most of their fighters from direct combat!
They left sixty-four active combatants — enough to avoid accusations of cowardice — but the rest would shift into the medical corps.
For the sake of the village, they would invest their resources to train healers.
For the sake of the village, they would still leave warriors on the front.
Whichever way you looked at it, no one could call them selfish.
When women led, Yagami thought, they truly saw the world with sharper realism.