Arai led the two to another section of the border.
This area lay far from the route they had attacked previously.
After making contact with the Sunagakure shinobi stationed there and gathering information about Amegakure's movements, the three rested for a day.
Then, late at night, they crossed the border again.
The procedure was the same.
Arai concealed himself in the shadows, silently observing while ensuring they wouldn't be overwhelmed.
Yuji and Sasori acted independently.
With experience from the first infiltration, both moved with greater familiarity this time.
Before splitting up, Sasori crossed his arms and looked at Yuji coolly.
"If you lose again, you won't have anything to say."
His tone carried faint arrogance.
This time, he seemed determined to win cleanly, without causing a premature alarm.
Yuji scratched his head and smiled.
"I was never your match in the first place. You're a genius puppeteer. I'm just a medical-nin."
His voice was relaxed, almost careless. He truly didn't care much about the competition.
Those words made Sasori's brows knit slightly. There was something irritating about that answer.
Without replying, he vanished into the trees.
Yuji slipped into concealment as well.
Moments later, through a narrow gap in the leaves, a pair of eyes watched two Amegakure patrol shinobi.
They moved casually through the forest, chatting as they ran along the branches.
Yuji unwound the piano wire from his fingers.
Swish
The two shinobi landed on a tree trunk.
The instant one stepped forward, a silver flash cut through the air.
His head separated cleanly from his body.
"What?!"
The second shinobi's pupils shrank. He had seen only a glimmer of light.
No attacker.
Swish.
This time, being alert, he caught sight of the weapon. A thin, almost weightless blade slicing through the air at terrifying speed.
Even at full velocity, it made almost no sound.
By the time he saw it...
Too late.
If he had sensed its trajectory earlier, he might have dodged. But the attack had been too insidious.
Too sudden.
In the next instant, his head followed his companion's, spinning through the air as blood sprayed across the bark.
Swish.
The blade curved midair, drawn back by invisible tension, disappearing into the canopy where Yuji crouched.
At the same time, nearly invisible wires wrapped around the falling corpses, dragging them silently into the undergrowth.
Yuji examined the wire coiled around his fingers.
"Not bad," he murmured inwardly.
"Still, since it's not directly hand-controlled at all times, the cutting angle isn't perfectly optimized. There's more blood spatter than I'd like."
Room for refinement.
He tilted his head slightly.
"If Arai is watching… I'll need a name for this technique."
He thought briefly.
"Blade Manipulation."
Yes.
He could claim the inspiration came from Sasori's chakra threads, an extension of puppeteer mechanics applied to ninja tools.
On the surface, wire-based combat wasn't rare. But what Yuji was doing wasn't ordinary wire control.
The system's assimilation had preserved the core mechanics of the original ability.
An ordinary shinobi couldn't replicate it.
For example, Sasuke Uchiha once used nearly invisible wires in combination with his Sharingan during his battle against Orochimaru, coordinating them with hidden weapons and Fire Release to create deceptive attack patterns and restrict his opponent's movement.
Yuji's piano wire wasn't ordinary.
It had been specially crafted, thin to an unnatural degree, almost impossible to detect with the naked eye in combat. Under moonlight, it reflected nothing.
To an observer, it looked as though the scalpel itself were dancing through the air.
And in truth, Arai was watching.
He remained concealed not far away.
Compared to Sasori, he was more concerned about Yuji. Sasori had already proven himself repeatedly in dangerous situations. Yuji, despite his rapid growth, was still technically a genin.
Arai had no intention of letting him fall here.
But when Yuji unleashed his new technique, Arai's eyelids twitched.
He was positioned at a distance. From movement to kill, everything happened too fast.
He couldn't see it clearly.
"Was that… the scalpel?"
"What kind of technique is that?"
Arai wasn't certain.
During their previous infiltration, Yuji had relied purely on close-quarters assassination. He had never displayed anything like this.
Soon, as more Amegakure shinobi arrived to investigate the missing patrol, Arai shifted closer and focused.
This time, he saw it.
The scalpel curved midair.
It was being pulled by something.
A thread.
It resembled a puppeteer's control method, except instead of manipulating a puppet body, Yuji was remotely guiding a blade.
What unsettled Arai wasn't just the control.
It was the range.
At that distance, the scalpel still retained remarkable speed and force.
And the stealth...
That wire was extraordinary.
Combined with the slim profile of the scalpel, it created a near-perfect assassination tool.
"There's some ninja tool technique in it, some hidden weapon influence, but it also resembles chakra threads," Arai thought, deeply puzzled.
He had never seen this ninjutsu before.
"If it were me, I could defend against it," he assessed calmly. "But in an unexpected environment, with a distracted mindset, even a Jonin could be caught off guard."
He inhaled quietly.
So Yuji had been hiding this.
He hadn't even used it during the previous mission, when they were nearly overwhelmed.
Just how many more things was this kid keeping concealed?
For the first time, Arai felt he didn't fully understand Yuji. The boy was becoming difficult to read.
"He says he doesn't want to become a puppeteer," Arai thought wryly, "but he's already laid half the groundwork."
He let out a silent sigh.
On the other side of the forest, Sasori had begun his hunt as well.
This time, he wasn't flamboyant.
His movements were controlled, precise.
Puppet threads extended silently through the canopy, guiding lethal constructs into position.
Targets fell one by one.
Unlike before, he erased his traces carefully.
If the first infiltration had been brazen, this one was surgical.
Time passed.
Gradually, too many patrol units failed to report back.
Amegakure's defensive line stirred.
Shinobi began moving in larger formations through the forest. The air grew tense. The search radius expanded.
But this time, Arai's trio was prepared.
They did not panic. As the mission time reached one hour, Arai gave the withdrawal signal.
Under the cover of the enemy's large-scale search, the three slipped away quietly without being cornered.