Chapter 22 — Kurama Yakumo
While chaos brewed in the Hokage's office, Aizen Sōsuke stood quietly before a laboratory console, his gaze fixed on the scarlet eye suspended inside a transparent containment capsule.
Supported by chakra, the lone Sharingan floated weightlessly.
Surrounding instruments blinked rhythmically, and the room was filled only with the soft hum of electronic circuits.
Through various detection devices, Aizen observed—in exquisite detail—the internal chakra pathways of the eye, as well as a strange, anomalous power embedded deep within it.
"So this… is the 'ocular power' the Uchiha speak of?"
Aizen pushed up his thick glasses out of habit. His calm expression held a faint shade of curiosity.
Chakra—a universal, all-purpose energy—had radically transformed this world.
Despite still being in a feudal era socially, its technology progressed as though unshackled by any limitation.
Over centuries of development, the ninja world had gained a deep understanding of its many forms of power:
Chakra
Natural Energy
Religious spiritual force
Sage arts
And now, ocular power.
Ocular power, however, was unique. Unlike natural energy, it could not exist independently; it demanded a massive reserve of chakra to sustain it.
"A fascinating form of power," Aizen murmured, "and—provided there is enough chakra—one that can be used even without Uchiha blood."
He set down the instrument, and his thoughts drifted to a certain "friend" of his—
Hatake Kakashi.
If only there were a way to let him open a Mangekyō Sharingan of his own…
That would be useful.
"If ordinary Sharingan awaken through intense emotional stimulus, mediated by a special chakra secretion in the brain…"
"Then the Mangekyō stands a level above."
"To maintain that heightened chakra state, one must fuse a powerful conviction with an overwhelming Yin Release—one strong enough to create matter from nothing, branding that conviction onto the very soul and imprinting it into the eyes."
"That… is the essence of the Mangekyō."
"And that essence crystallizes into each Mangekyō's unique pattern—
and from that, its unique ocular technique."
Aizen continued scribbling notes onto the Root archive documents, analyzing each detail with clinical precision.
"Unfortunately, Mangekyō ocular power appears to be fundamentally consumable—a one-time burst of belief, sustaining the ability only until its chakra base is exhausted."
"Each belief becomes a technique."
"When that belief burns out… so do the eyes."
"That's consistent with Root's data—long-term Mangekyō activation leads to blindness."
"So the question becomes—how does one make a Mangekyō sustainable?"
His pen hovered mid-air.
Whether collecting Sharingan or acquiring God-Tree genetic material, all of it was in service of a single goal:
To forge a Zanpakutō of his own.
A weapon that belonged exclusively to him—
and that would grant him true freedom to act.
Aizen had no intention of creating something as fragile or disposable as the Mangekyō.
But research could not be completed purely by theory.
Even he couldn't solve everything by thinking alone.
"I need to observe, firsthand, the evolution from Sharingan to Mangekyō."
"And if possible… I will need multiple subjects for comparative study."
"Uchiha Itachi… hmm?"
Aizen's eyes narrowed faintly, as though he had just seen a very interesting piece fall into place on a grand chessboard.
Aizen's pen paused over the paper, tapping lightly as a quiet smile curled at the corner of his lips—
as though he had just thought of something interesting.
It seemed his plans needed to accelerate.
---
Knock, knock.
His thoughts were interrupted by a soft knocking from the room aboveground.
Aizen only needed the slightest use of his perception to recognize the identity of the visitor.
Not surprising, really.
He straightened his clothes, smoothed out his expression, left the underground chamber, and ascended to the surface room.
When he opened the door, he was greeted by the sight of Yūhi Kurenai, standing there with an inexplicably annoyed expression.
"Kurenai? What are you…?"
Aizen—wearing loose loungewear in his disguise as Sōsuke—blinked in apparent confusion as he opened the door.
"Don't tell me you forgot!" Kurenai scolded, one hand on her hip.
"We agreed to visit the Kurama clan today to examine their daughter!"
"Ah—right, right! My apologies!"
Sōsuke quickly pressed a hand to his forehead, wearing a flustered expression.
"Give me just a moment to get ready!"
"You'd better hurry!"
"Yes, yes!"
---
Before long, the two—now properly dressed—stepped out the door and headed toward the Kurama clan's compound.
Along the way, Kurenai briefed him on the situation.
The Kurama clan, she explained, had historically produced a powerful illusion-type bloodline every few generations—
a genjutsu so potent that at its peak, a Kurama prodigy could stand shoulder-to-shoulder with even Uchiha elites.
This generation's inheritor of that bloodline was the clan's eldest daughter:
Kurama Yakumo.
Her talent had manifested when she was still very young.
Her parents, recognizing her extraordinary potential, hired Kurenai—one of Konoha's most skilled illusionists—as a private tutor, preparing to raise her into a formidable shinobi.
But during training, Kurenai discovered the problem:
Yakumo's body was far too frail to support such overwhelming power.
Her bloodline ability placed a devastating burden on her health.
Over the years, the Kurama patriarch had invited experts from all across the village, but none were able to help her.
More recently, even her parents seemed close to giving up.
---
"Lord Murakumo, Lady Rin."
When they arrived at the Kurama estate, Aizen and Kurenai sat across from the clan head and his wife.
Kurenai, acting as the formal host, introduced him steadily:
"This is Aizen Sōsuke, a jōnin and current head of Konoha's Third Research Division.
He developed a unique bloodline-derived technique known as Hikariton—Light Release—two years ago, based on Yin Release principles."
"He is one of the few in Konoha capable of conducting direct research into the spiritual plane."
Unlike her casual attitude in private, Kurenai was completely professional now.
The Kurama couple—both jōnin themselves—looked surprised as they studied the young man before them.
To create an entirely new bloodline-derived technique was a rare achievement even across the whole shinobi world.
It was precisely this accomplishment that explained how someone with seemingly average combat ability was able to rise to jōnin so quickly.
Rumor had it that Light Release allowed the user to manipulate light and illusions through pure Yin Release—
"weaponizing the mind to bend reality."
Such a technique implied terrifying mastery.
What surprised them most was simply:
He was this young.
Perhaps… there really was hope?
The couple exchanged a glance before bowing politely.
"Aizen-dono, you are truly accomplished at such a young age."
"The name 'Light Release' is well known to us."
"We humbly ask that you do everything within your power today.
If you can cure our daughter, the Kurama clan will forever be in your debt."
Aizen responded with the same gentle, springlike smile that disarmed nearly everyone who faced him.
"Just a small technique—I hardly deserve such great praise from Lord Murakumo."
As he spoke, he glanced toward the timid girl peeking from behind her parents.
"This must be young Lady Yakumo?"
"Yes," the clan head affirmed.
Hearing her name, Kurama Yakumo sat upright and shuffled closer to her parents, her expression shy—
Yet her eyes held unmistakable hope.
To become the strong shinobi her parents dreamed of—that was her greatest wish.
Even a sliver of hope was worth clinging to.
Aizen studied her quietly.
To control the five senses… to make illusion manifest as reality.
What an intriguing power indeed.
And a useful one.
--