A white beam of light rose from the center of the plaza.
A black cube burst from the ground—each of its four faces carved with a different expression: joy, anger, sorrow, and pleasure. A thick, malevolent chakra oozed from its surface.
"That thing… is that the Box of Ultimate Bliss?"
This feeling… is bad.
Kiyosuke's instincts screamed at him—that thing must never be opened.
The warden of Hōzuki Castle, Mui, stepped forward and raised both hands.
"Box of Ultimate Bliss, grant my wish!"
Behind him, four Grass Village elders wearing animal masks quivered with excitement. Finally, they could wield the power of the Box of Ultimate Bliss. With it, Kusagakure could once again dominate the world.
Once upon a time—long before Kusagakure even existed, before the Land of Grass was founded—there had been a group of people who borrowed the power of the Box of Ultimate Bliss. That era was so ancient it could be traced back to the time of the Sage of Six Paths. Those people nearly conquered the entire world, but in the end, they failed.
That power was not something humans could control.
Even so, the elders believed that Mui—who had inherited the sealing techniques passed down for generations—could control it.
He was their most loyal subordinate, a man willing to sacrifice everything for Kusagakure… even his own son.
By that logic, the elders told themselves, it was practically the same as they controlling the Box's power.
They would use it to conquer the world.
The Five Great Nations? The Five Great Shinobi Villages?
Before the might of the Box of Ultimate Bliss, all would crumble like dust.
They—the true heirs of the Grass—would lead Kusagakure to rule the world!
Just picturing that scene made them tremble with anticipation.
"Come on! Make your wish to conquer the world! Even your late son would be proud of you!"
"Hurry! Hurry! The Box of Ultimate Bliss can grant the warden's wish!"
They were practically jumping with impatience, as though they were the ones making the wish.
But...
A deep sorrow flashed in Mui's eyes.
"Box of Ultimate Bliss… now is the time to open! Box of Ultimate Bliss!"
The face on the cube seemed to hear him.
A wave of heavy, sinister chakra burst forth.
"This feels… so wrong."
From a nearby rooftop, Kiyosuke watched the scene unfold. His gaze swept to Naruto—battered and weak, his chakra clearly drained. He must've been used as the key to open the Box.
Still, it wasn't too serious. Even if his chakra was restricted, extracting that little bit from a descendant of the Uzumaki Clan—a Jinchūriki of the Nine Tails—was nothing to worry about.
Tears streamed down Mui's face.
"Box of Ultimate Bliss… please… let me see my son again. Please… return Muku to me!"
That was the one thing he regretted most in his life.
Under the elders' orders, he had sent his beloved son into the Box of Ultimate Bliss. Every sleepless night since, he had hated himself for it. He could never forgive the elders, never forgive himself. He had no desire to open the Box again—yet to see his son even once more, he pretended to obey their commands and waited for this day.
"Box of Ultimate Bliss! Grant me my wish!"
"What?!"
The elders froze in shock.
Where was their loyal Mui—the man willing to sacrifice everything for Kusagakure?
Why had he betrayed them?!
"Mui! What are you doing?! Haven't we worked all this time for Kusagakure's sake?!"
Mui's expression softened with quiet sorrow.
"In my heart, Kusagakure ceased to exist the day I lost Muku—ten years ago."
"You bastard!"
"Die!"
The four elders leapt at him.
But a blur of movement cut through the air—
A bald man wielding a scythe stepped between them.
It was Kazan—the same shapeshifter who had disguised himself as Naruto and framed him to be imprisoned in Hōzuki Castle.
"You—you were supposed to be dead! We killed you last night!" the elders shouted in fury and disbelief.
"Tch! Mui saved me. What a pain… You bastards used me as a pawn! If it weren't for my son—!"
Before he could finish, Kiyosuke dropped from above and struck one of the elders dead with a single blow.
"Well, this looks lively. Mind if I join in?"
"Y-you're—!"
The tiger-masked elder stumbled back, pointing at him with trembling fingers.
"H-How are you here?! No—you shouldn't be here! Asakawa Kiyosuke?!"
"Why do you care why I'm here?" Kiyosuke snorted. "You people have been taking good care of my kid lately. I'll be sure to return the favor."
He kicked another elder straight into a wall—the man crumpled to the ground, unmoving.
"Damn it!"
Kiyosuke ignored the rest, his attention fixed on the Box of Ultimate Bliss.
"My friend," he said calmly, "that thing really shouldn't be opened."
But Mui no longer heard him.
The faces on the cube began to peel away, revealing a ghastly visage beneath—grim and hollow-eyed.
"So that's the Box's true seal?"
The carved face opened its eyes—then its mouth.
From within the darkness, a ragged figure stepped out—a pale young man, perhaps twenty years old, with lifeless eyes and tattered clothes.
"Muku…"
In the distance, a white-haired girl covered her mouth in shock.
She couldn't believe her friend was still alive.
"Muku…"
Mui stepped forward, arms trembling, desperate to embrace his son.
"Father."
Muku lifted his head to look at him.
"Muku, I'm sorry…"
But Muku's expression twisted.
His eyes filled with fury.
He lunged forward—and drove his arm straight through his father's chest.
"What?!"
Everyone froze.
Even the prisoners watching were dumbstruck. For a moment, none of them could comprehend what had just happened. Then a thought flickered through their minds—
If Mui's dead… can we escape?
In an instant, chaos erupted. Prisoners dashed for the gates.
"Damn… a truly filial son," Kiyosuke muttered, watching Kazan rush forward—only to get himself killed next.
He sighed and shook his head.
"That guy's not the same person anymore."
After all those years trapped inside the Box, who knew how he'd survived?
Even a few days locked in solitary confinement could break a man—let alone ten years in total darkness.
"You shouldn't have let me out, Father," Muku sneered.
The world around him fell silent.
The maddening voices in his mind were gone. The chaos within him vanished.
"Ah… this feeling… it's wonderful," he whispered, his face twisting in bliss.
Muku reveled in the silence—utterly consumed by it.