Hiroki's lips curved upward.He'd finally figured out how to deal with Kakuzu.
His gaze focused on a single line of code pulsing across the interface:
[packet.check_code = calculate_hash(packet.content + key);]
That was it.
The check code—the hash key—was the linchpin of the whole protocol.In ordinary terms, it worked like a company's official seal: both sides used it to verify any information sent between them. The hash itself was a one-way encryption process—data of any length was transformed into a fixed-length signature that couldn't be reversed.
Once something was hashed, it stayed that way.It was like taking a pile of sugar, a bit of carbon dioxide, and a bottle of water, then mixing them into soda. You could taste it and know it's soda, but you'd never be able to separate the ingredients again.
Unless, of course, you knew the recipe—the key.
With that, you could instantly tell whether what you were drinking was cola… or toilet cleaner.
In short, the hash key was everything.It was the seal of authority, the master signature that authenticated every action.
And Hiroki had just found it.
Normally, such a key would be stored securely on the main server—never on remote terminals.Like a company's CEO sending an intern for coffee; he might hand them a bit of cash, but he'd never give them the company stamp.
But Kakuzu wasn't a server.He was a person. A human being who just happened to be distributed across multiple bodies. Why would someone ever think they needed security protocols between their own limbs?
To Kakuzu, walking around with his "official seal" inside him was perfectly normal.And to Hiroki, that mistake was a godsend.
Kakuzu had no idea what a hash function even was.This entire digital structure—the protocols, the keys—existed only because Hiroki's strange, otherworldly "system" translated them that way.
Back in reality.
Barely a few seconds had passed.Kakuzu was still sneering, his voice dripping with amusement.
"So, your little poison works on me too? That's a first. What kind of ninja are you, kid?"
In his sixty or seventy years of existence, nothing had ever managed to interfere with his reconstructed body.After being reshaped by the Earth Grudge Technique, his blood, skin, and heart were little more than tools. His true self was the mass of black tendrils within—the pulsing network of chakra threads that held him together.
Yet now, one of those tendrils had gone completely dead.
Hiroki didn't reply. He just stood there, lost in thought, staring at the severed tentacle in his hand.
"What's wrong, cat got your tongue?" Kakuzu growled, narrowing his eyes.
Something felt… off.
His Fire Mask shifted forward, preparing to attack again.That brat—he'd been fiddling with the tentacle nonstop, like a scientist dissecting a specimen. What did he think he was doing? Analyzing chakra composition? Trying to unlock immortality from a dead piece of flesh?
Ridiculous.If the Earth Grudge Secret Technique could be cracked so easily, Kakuzu wouldn't be the only one in the world who'd mastered it.
Just a kid. Even with Orochimaru's help, there was no way he could—
The thought stopped cold.
A strange sensation rippled through Kakuzu's consciousness, sharp and alien—like a drop of water splashing into hot oil. Something was wrong.
His gaze snapped back to Hiroki.
Was that kid… smiling?
Fire Style: Searing Head!
Flames erupted from the Fire Mask, roaring across the battlefield. Orochimaru turned immediately, eyes widening.
No! Hiroki!
The boy was still motionless, staring at that tentacle, grinning faintly.
It was too late for Orochimaru to reach him. He gritted his teeth and prepared to unleash a sealing jutsu, even if it meant taking the blast himself.
But Hiroki didn't flinch.
Everyone knew what you did the moment you stole a rival company's official seal.You didn't destroy it.
You used it.
And in system terms, a contract was just a data packet—a formalized command.All Hiroki had to do was create an API request that followed the format defined in EarthGrudgeProtocol.dll, and he could issue commands directly to Kakuzu's distributed network.
And he did it fast.
In a flash, Hiroki typed out the command. It deployed instantly into the tentacle still in his hands.
The tendril twitched.
The Fire Mask launched its attack, a wave of searing heat consuming the space ahead. Kushina gasped, reaching out instinctively.
"Hiroki!"
Nawaki froze, horror washing over him as the inferno swallowed the boy's silhouette. For a moment, it looked as though Hiroki had vanished into the blaze.
Then—
"Earth Grudge: Umbrella!"
Hiroki's voice was calm. Cold.
From the severed tentacle in his hand, countless black cords exploded outward, weaving together at impossible speed—forming a dense, spiraling dome of tendrils.
The wall of flame slammed into it head-on.
The inferno roared. The tentacle shield held.
Everyone—Kushina, Nawaki, Orochimaru—stared in stunned silence.
Even Kakuzu.
Impossible.
The very same tendrils that once obeyed only him… were now protecting someone else. Acting on commands that weren't his own.
His mind reeled.
That jutsu—Earth Grudge: Umbrella—he'd never even heard of it. He'd never created anything like that.
And the voice that had issued the order…
It had come from that boy.