Recently, Urahara Kisuke had been in a terrible mood.
As the 4th Seat of the Shino Prison, he didn't have to busy himself with various squad duties, dossiers, or document sorting like the seated officers of the Gotei 13.
There were no strict rules or regulations binding him in his daily life.
His direct superior only had one requirement for him: to focus on his research and push his world-shaking intellect—second only to a certain someone's—to its absolute limits.
He was expected to develop all sorts of black technology to benefit the Soul Society and the Seireitei.
Because he loved research, he had initially embraced this role with open arms.
But as time passed, when his former hobby turned into a mandatory job, it started to feel somewhat torturous.
This was especially true because his boss was petty and couldn't stand seeing anyone idle.
He was frequently assigned tasks that ordinary people would consider pure fantasy, with grueling deadlines measured in months or even years.
Urahara Kisuke had strongly protested this, bluntly stating that if this continued, he would draw his invincible Benihime and commit insubordination, turning the hierarchy upside down.
He was then severely punished and met with an iron fist by a certain someone.
Although life was a bit depressing, it was generally acceptable.
As time went on, Urahara Kisuke gradually grew accustomed to this lifestyle, even voluntarily throwing himself into research tasks that weren't originally his responsibility.
By the time he realized what was happening, he couldn't help but feel a sense of horror.
*'Kisuke, oh Kisuke, how did you become so unrecognizable?'*
*'You, who once considered slacking off to be your life's creed, were actually manipulated by some meathead?'*
*'I don't want this!'*
Just as he was trying to accept this chilling reality, Naraku Sora suddenly brought a new colleague to the Department of Research and Development.
The former 3rd Seat of Squad 5, now the Lieutenant of Squad 5, Aizen Sōsuke.
Initially, Urahara Kisuke didn't think much of it.
In his eyes, Aizen might have some talent in scientific research, but he definitely couldn't compare to him and Kurotsuchi Mayuri, who had been immersed in the scientific field for years.
However, as they interacted more, Urahara Kisuke was shocked to discover that this man named Aizen Sōsuke was anything but simple.
Whether it was his talent or his capabilities, he was absolutely top-tier.
Looking across the entire Soul Society, one would be hard-pressed to find more than a few people smarter than him.
No matter how complex the topic or project, as long as it was handed over to Aizen, it would be completed in just a few days, often even more perfectly than anticipated.
Even Urahara Kisuke couldn't guarantee he could do it better.
He had originally thought that the strong alliance of the Department of Research and Development's trio would kick off an epic journey of scientific discovery in the Soul Society.
But through continuous interaction, Urahara Kisuke discovered the wild, wolf-like ambition hidden beneath Aizen's gentle and humble exterior.
This man was definitely not as simple as he appeared on the surface.
Considering the close friendship between him and Naraku Sora, the two of them hung out together all day.
Most importantly, Naraku Sora never doubted a single word Aizen said.
It made sense when he thought about it. His boss's brain was entirely made of muscle—at most, he had an extra tumor in there. Facing a scheming figure like this, he definitely wouldn't be able to see through his true colors.
Aizen only needed to use a few minor tricks to run circles around him.
It might not be obvious in the short term, but once the man revealed his true ambitions, he would inevitably drag the Seireitei, and even the entire Soul Society, into an abyss of eternal doom.
Subconsciously, Urahara Kisuke was already treating Aizen as a threat of the highest caliber.
He knew very well what kind of terrifying crisis someone like himself could cause if they intentionally chose to do evil.
In order to nip the danger in the bud, he began investigating Aizen.
However, the man acted with extreme caution, leaving absolutely no traces to be found.
All signs indicated that Aizen was merely a Soul Reaper with a slight talent for scientific research, possessing no decent strength to speak of.
Urahara Kisuke had been ready to give up, but during one instance of welcoming Naraku Sora back, he suddenly detected a trace of Reishi fluctuation on his boss that didn't belong to the Soul Society.
*'It's Hueco Mundo!'*
Urahara Kisuke suddenly understood.
No wonder he couldn't track Aizen's movements; the man had been hiding all his evil deeds in Hueco Mundo.
The most terrifying part was that his boss had already been bewitched by the other party, completely reduced to an accomplice.
This was no ordinary villain.
He had to strike hard and fast.
Urahara Kisuke's desire to uncover the truth had never been as urgent as it was today.
Avoiding Kurotsuchi Mayuri, he privately developed a black cloak capable of perfectly concealing his Reiatsu.
Using this, he actively infiltrated Aizen's exclusive laboratory within the Department of Research and Development, searching for evidence sufficient to convict him.
Yet, despite all his efforts, he still found nothing.
Just as Urahara Kisuke was pondering whether he should take a trip to Hueco Mundo to investigate, he suddenly discovered a few pages of handwritten documents in Naraku Sora's office.
*'What is this?'*
Urahara Kisuke knew very well that his boss disliked reading. Although he had an exclusive office set up in the Department of Research and Development, its symbolic meaning far outweighed its practical use.
Naraku Sora usually used it to issue orders and make empty promises to his subordinates.
*'So this document definitely has something to do with Aizen!'*
Realizing this, Urahara Kisuke quickly examined it.
There wasn't much content, only a mention of an untapped power existing deep within the souls of Hollows.
And...
A whimsical, fantastical hypothesis.
Gradually, only dead silence remained in the office, accompanied by his increasingly rapid breathing and heartbeat.
A short while later, a figure draped in a black cloak, concealed by the Kyokkō Bakudō, quietly left the room.
In a corner of the corridor that no one noticed, under the imperceptible glow of a Kidō spell, a figure slowly emerged.
Naraku Sora watched the retreating back, revealing a satisfied smile.
*'Kisuke, sooner or later, you will understand—'*
*'In this world, I am the only one who truly understands you.'*
For a long time after that, Urahara Kisuke squeezed out time from his busy schedule to study the contents mentioned in the document.
At the same time, he began collecting the various materials needed for the experiment.
For example, the most important one: the souls of Menos Grande.
Although there was stock left in the warehouse, they were all registered. If even one went missing, there would be a thorough investigation from top to bottom.
As a result, Urahara Kisuke began making multiple trips to the Rukongai, searching for Menos Grande that had accidentally invaded the Soul Society.
Over the course of a few months, he actually managed to obtain a few rare specimens.
Although they were only the lowest-class Gillian, they were enough for preliminary experiments.
However, researching the unknown was addictive.
Even though Urahara Kisuke repeatedly warned himself that privately researching how to break the soul boundary between Soul Reapers and Hollows was a taboo strictly forbidden by the laws of the Soul Society...
As a researcher, he simply couldn't resist the thrill of solving a difficult problem step by step.
When the materials ran out and he could no longer find any Menos Grande in the Rukongai, Urahara Kisuke fell into a dilemma once again.
*'My boss is nowhere to be seen all day, and my work is already finished. It shouldn't be a problem if I take a trip to Hueco Mundo during my free time, right?'*
*'I might even find evidence of Aizen's treasonous intentions!'*
After careful consideration, Urahara Kisuke pulled out his trump card technology and opened a Garganta to Hueco Mundo in a hidden location in the Rukongai.
Because it wasn't his first time going to Hueco Mundo, he smoothly found the materials he wanted in the boundless desert.
A few Gillian wandering in the sea of sand.
Behemoths tens or even hundreds of meters tall, wandering aimlessly like giant whales in the deep sea.
With Urahara Kisuke's strength, a few Gillian posed no threat at all.
He didn't even need to draw his Zanpakutō; just a few Kidō spells were enough to end the battle.
Before long, he returned to the Soul Society with his materials, thoroughly satisfied.
Realizing that no one was paying attention to his actions, Urahara Kisuke threw himself back into his experiments.
Because he had prior experience, he was exceptionally cautious when researching taboo subjects this time.
Not only did he avoid conducting them in the Department of Research and Development, but he even went out of his way to build a new laboratory in the Rukongai.
After the first time, there was a second, a third...
From the initial Gillian to the later Adjuchas, mutant Hollows with special abilities.
His harvests grew increasingly abundant.
Until he encountered three bizarre creatures that looked no different from humans.
"Recently, Gillian have been disappearing from this area. I thought an Adjuchas skilled in slaughter had been born, but to think it was a Soul Reaper."
The person speaking had choppy blue hair, a rebellious expression, and eyes filled with unconcealed arrogance and wildness. He wore a standard white uniform with a blade slung at his waist.
"A guy like you should be killed on the spot, but the King said that Las Noches is short on food lately. If we spot a Soul Reaper, we're to capture him and bring him back."
"He wants to slice your meat thin and boil it for a meal."
Hearing this, Urahara Kisuke's pupils shrank, his expression turning incredibly grim.
Although these people looked human, judging by their Reiatsu signatures, they were all Menos Grande.
And each one was stronger than the last. This time, things might be a bit tricky.
Fortunately, he had come prepared.
"Hadō #63: Raikōhō!"
There was no time for idle chatter. The moment he realized the newcomers harbored ill intent, Urahara Kisuke began accumulating his Reiatsu. Catching them off guard, he blasted a hundred thousand volts straight into their faces.
Golden lightning tore through the air, causing the desert to tremble.
Grimmjow never expected the Soul Reaper that Naraku Sora had taken an interest in to be so despicable. Caught off guard, he took the full brunt of the attack, his entire body instantly submerged in the violent, surging electrical arcs.
Seizing the opening, Urahara Kisuke drew his Zanpakutō with a swift motion.
"Sing, Benihime!!"
The moment his voice rang out, a dazzling red sword pressure erupted from the bent blade. The sound of it tearing through the air was fleeting as it directly dragged Ulquiorra, who was standing next to Grimmjow, into the fray.
Urahara Kisuke knew very well that none of these three were pushovers.
He had to pin them down immediately and then look for an opportunity to escape.
While unleashing the sword pressure, he raised his left hand and fired an incantation-abandoned Sōren Sōkatsui straight ahead.
The instantly blooming explosive flames completely engulfed Nnoitra.
Without any hesitation, Urahara Kisuke wore a solemn expression. He flipped his wrist, pointing the tip of his blade downward, and softly chanted his release command:
"Bankai—"
"..."
*Squelch—*
The sound of flesh tearing echoed from behind, forcibly interrupting the release of his Bankai.
Enduring the agonizing pain, Urahara Kisuke turned his head in shock, only to see a figure draped in a black cloak standing behind him.
In his daze, he seemed to catch the glint of glasses.
*'It's you, Aizen Sōsuke!'*