Muken
A figure hurriedly stepped inside.
Yamamoto narrowed his eyes, scanning his surroundings.
Despite the oppressive darkness, he could see everything with absolute clarity.
Not long ago, he had received an urgent report from his subordinates.
According to the report, the Special Forces Unit had discovered a mass of unexplained deaths within the depths of the underground prison beneath the Shin'ō Academy.
Most notably, in the lowest level—Muken—only one prisoner remained alive: Kenpachi Azashiro.
Upon hearing this, Yamamoto had been immediately unsettled.
The prisoners in Muken were monsters—each one a force of destruction from their respective eras.
If they had all perished… the repercussions on the world's balance would be catastrophic.
Without hesitation, Yamamoto had set out to investigate the situation personally.
Under normal circumstances, even as the Captain-Commander of the Gotei 13, he would have been required to submit a formal request to the Central 46 for entry into the underground prison.
The process involved multiple layers of approval, an absurd bureaucratic tangle.
Even the Special Forces Unit responsible for patrolling the facility had to submit reports an entire month in advance.
But right now, Yamamoto had no patience for protocol.
The crisis unfolding in Muken was immediate—a potential worldwide threat.
There was no time to wait for those incompetent, self-serving officials to issue orders.
Ignoring the guards' futile attempts to stop him, Yamamoto forced his way through every barrier and restriction, heading straight for Muken's depths.
His eyes burned with an eerie, flaming-red glow, cutting through the shadows like they pierced the very darkness itself.
But when he arrived…
There was nothing.
No sign of forced entry.
No evidence of a battle.
No scorch marks, no bloodstains, no unnatural disturbances in the environment.
Even the prisoners…
Not a single one of them was still alive.
Yamamoto's pupils contracted sharply.
As Captain-Commander, he knew exactly how many inmates were sealed within Muken.
He was personally aware of each and every one of their names, crimes, and levels of power.
And beyond that—he held absolute control over every barrier in this hellish abyss.
In an instant, he reached a chilling conclusion.
Aside from Sōya Azashiro, the former Captain of the 11th Division…
Every single prisoner in Muken was dead.
Yamamoto's heart sank.
To silently exterminate so many monstrous beings…
This was no ordinary act of violence.
No common Shinigami could have accomplished this.
Muken, buried deep beneath Squad 1's headquarters, was as ancient as Seireitei itself.
Its origins stretched back to the very founding of the Gotei 13.
For centuries, it had been his hand that had sentenced countless criminals to this abyss—directly or indirectly.
He was a witness to its long and bloody history.
He knew every prisoner's strength.
And some of them…
Some had been here since the very birth of the Gotei 13—legendary warriors strong enough to battle the original Captains to the death.
And yet, now…
They were all gone.
Their deaths would send shockwaves across the Three Worlds.
Yamamoto inhaled deeply.
His figure flashed, vanishing in an instant as he rushed into a solitary cell.
And when he finally saw the lone surviving figure within…
The weight on his chest eased—just slightly.
He let out a sigh of relief and spoke softly.
"Kenpachi Azashiro, do you know what happened here?"
But after a long pause, there was no response.
The old man's brows furrowed. His voice grew sharp as he barked,
"Sōya Azashiro! Can you hear me?"
The tension inside the cell became suffocating, as if time itself had frozen.
Yet, Sōya Azashiro remained motionless, lying there like a corpse, silent and unresponsive.
Suddenly, Yamamoto whirled around, his piercing gaze locking onto the guards who had followed him.
His voice exploded through the cell like a thunderclap.
"Send for Captain Unohana and Captain Urahara immediately! Tell them it's an emergency!"
The guards froze in place.
Never before had they seen this side of the Captain-Commander.
The man who was usually composed and unshakable now stood before them visibly shaken.
For a brief moment, they hesitated, exchanging uncertain glances.
But Yamamoto did not have the patience for hesitation.
"Go!"
His roar was deafening, sending a tremor through their very bones.
The guards flinched, then snapped to attention.
"Y-yes! At once!"
They turned on their heels and sprinted away.
Now alone in the suffocating stillness of the cell, Yamamoto stood motionless.
...
Seireitei – Noble District.
"How much for this one?"
Aura Michibane asked.
The elderly shopkeeper behind the counter grinned, revealing a set of pristine white teeth.
"Ah, Miss Michibane, you've got a keen eye! This is the latest model—there's not another one like it in all of Soul Society!"
"Since you're a member, I'll give you a special price. 1.2 million Kan."
"Hmm..."
Aura Michibane hesitated for a few seconds, about to decline.
For some time now, she had felt a growing desire for a child.
But she also knew that Masatsuki Aozaki had his reservations.
When the time came, he always took precautions.
And so, she had no choice but to channel her unfulfilled maternal instincts into collecting these adorable dolls.
She really liked this one.
But her room was already overflowing with them.
Not to mention, 1.2 million Kan for a single doll was excessive—even for her.
Even a Gotei 13 Captain's entire month's salary wouldn't be enough to buy two of these.
Masatsuki wasn't short on money, but still, she felt the need to show some restraint.
After all, for a scientist, self-control was important.
"Maybe next time—"
"Wrap it up."
A familiar voice cut through her thoughts.
Aura Michibane didn't even flinch. Instead, she smiled.
She knew that voice all too well.
Masatsuki Aozaki.
She had long since grown accustomed to his habit of embracing her from behind without warning.
"Masatsuki," she murmured.
Hearing her call his name, Masatsuki grinned, resting his chin on her shoulder.
"What a waste."
"Really? I don't think so."
A sly glint flashed in his eyes as he leaned in, whispering close to her ear.
"Take it. I have other gifts for you."
Gifts?
Aura Michibane raised an eyebrow, intrigued.
Her mind wandered back to a certain promise Masatsuki had once made to her.
Surely, it hasn't been that soon already…?
Curious yet doubtful, she let him take her hand as they walked toward the laboratory.
Once inside, Masatsuki casually lifted a hand and snapped his fingers.
Snap.
A crisp sound echoed through the room.
The shadows at their feet suddenly stretched and unfurled, spilling out dozens of jade-like orbs onto the floor.
Each orb gleamed with a luminous radiance, their quality evident at a glance.
They landed with a series of sharp, crystalline clinks, as if deliberately showcasing their worth.
Aura Michibane's lips curled into a satisfied smile.
So these were the new experimental materials Masatsuki had gathered for her.
She narrowed her eyes, studying the orbs carefully, already calculating how best to use them for her next round of research.
"All Captain-class…" she muttered, eyes gleaming with fascination.
"What did you do?"
Masatsuki smirked.
"Just took a stroll through Muken."