Demon Slayer: The Journey That Began When I Became Yoriichi's Sister

Chapter 604 Collapse of Jade

Aizen placed a white stray hair on the table, and casually picked it up with tweezers to examine it closely.

Even in the stuffy basement, the severed hair moved on its own, swaying slightly without any wind.

The spiritual particle density contained within was indeed, as they perceived, a spiritual pressure quality unique to captain-level individuals.

Aizen placed the severed hair in front of the instrument, and as his field of vision magnified, an unimaginable fact unfolded before his eyes.

As is well known, the souls in Soul Society are all made up of spirit particles, whether it is the body, blood, or cells.

Just as the cells that make up hair in living organisms are dead cells that are not active, the hair of the soul should be the same.

However, under the observation of the instruments, the spiritual activity of this white broken hair was somewhat beyond imagination.

Logically speaking, the spiritual particles contained in hair should not retain such high activity.

This is different from the aura that comes from spiritual pressure; it's something that the hair itself possesses.

"interesting."

Aizen narrowed his eyes slightly, casually gathered a wisp of spiritual pressure at his fingertips, and slashed down at the hair.

The hair snapped off instantly; it wasn't any harder than regular hair, but something unexpected happened.

On the stage, two severed strands of hair were emerging from their cuts, their ends teeming with active spiritual particles, like living tentacles. They quickly connected with each other, and the structure of the spiritual particles was repairing and reorganizing at a speed visible to the naked eye.

In almost an instant, the hair returned to its original state, as if it had never been cut.

"...Super-fast regeneration."

Aizen adjusted his glasses. Although he had expected it, it was still surprising to see it actually happen.

and……

Such rapid regeneration, it's in no way inferior to those top-tier Hollows.

So what?

"Hado No. 4, White Lightning." Aizen stared at his hair, an even stronger spiritual power swirling around his fingertips, and a highly compressed white lightning bolt struck his hair precisely.

This time, the hair was instantly singed.

He deliberately held back some of his strength, not completely evaporating the hair.

And these strands of hair were exactly what he wanted, breaking free from the charred body like a cocoon breaking free and then reconnecting.

Aizen was truly moved this time.

There was no sign of it absorbing spiritual particles from the outside world; rather, the spiritual particles remaining within itself had not been completely eliminated.

This level of regeneration already surpasses the regeneration efficiency of those large voids.

It has been at least ten hours since the hair broke off. It has completely separated from the body and has not even relied on external spiritual particles. It has only relied on the spiritual particles remaining in the hair itself. This level of regeneration is unheard of even in the Great Void.

The power of death and Hollows...

Aizen's breath hitched for a moment as a thought suddenly arose in his mind.

"Hogyoku..." Aizen slowly uttered two words, his thoughts gradually becoming clearer.

The combination of Shinigami and Hollows—no, it should be said that it transcends the boundaries between Shinigami and Hollows.

He had always thought of himself as a pioneer at the forefront, but now the phenomenon shown by this strand of hair undoubtedly indicates one thing.

“Urahara Kisuke…” Aizen pushed up his glasses, his gaze gradually becoming more reserved.

No wonder, no wonder he said that a captain-level figure could appear in Seireitei without warning.

Aizen's lips curled into a slight smile; he hadn't misjudged him after all.

Urahara Kisuke...

That man certainly possessed intelligence superior to his.

So that's how it is. You really did end up on this path too.

She even walked ahead of him.

Aizen's plan to steal the soul modification documents was originally intended to test Kisuke Urahara.

So, did he succeed?

Aizen's gaze was fixed on the hair on the table, which had been completely restored. He could not sense any resemblance to Hollow from the spirit's aura.

Is this considered perfect, exceeding the limit?

……

No, it's not what he imagined.

Although his spiritual pressure level has reached the captain level, if he is only at the captain level, then as an existence that has transcended the limit, he is too weak.

It's not a success yet; it's just a defective product.

……

Suddenly, another thought arose in Aizen's mind.

Did Yamamoto Genryusai Shigekuni know about this?

It's impossible for them to know, right?

That stubborn old man, as the maintainer of order, would absolutely not allow such a thing to happen; he must have been unaware of it.

That's why the argument broke out at that time, but it was only managed to be smoothed over by Kisuke Urahara and Yoruichi Shihouin.

After all, there are plenty of reasons why there is no trace of anything related to the void.

I just don't know if they used some special method to hide it, or if they've already evolved to that point.

Therefore, his plan must be accelerated.

"You've really given me a tough challenge, Urahara Kisuke." Aizen's lips curled slightly; it wasn't a pleasant feeling to be outdone.

However, it doesn't feel too bad.

……

Several years have passed in the blink of an eye. Time in Seireitei seems to have stood still, yet it has flowed by unnoticed.

In the past few years, under Ikuko's guidance, Byakuya Kuchiki's swordsmanship has improved day by day, and he has already shown the potential to surpass his father.

Yuko remains stuck on developing her Bankai. No matter how she tries, she's even gotten annoyed by Yoruichi's nagging and has started trying to communicate with Butterfly, but Butterfly just won't tell her, even though there's no real emotional gap between them.

……

Or perhaps, she simply wasn't aware of this gap herself.

but……

Have it?

A gap in the heart?

She doesn't think she could have any emotional gap with him.

Yuko was puzzled and had no way to deal with the butterfly.

Although there was no improvement in her Bankai, Yuuko's spiritual power became increasingly refined, completely surpassing Yoruichi's.

Over the years, she has gotten to know almost all the captains of the thirteen divisions, and according to her estimate, they can at least rank in the top five.

Regarding her studies in Kido, she has already mastered advanced Kido techniques without chanting.

Sure enough, a high-level expert is a high-level expert; they really did hold her back for two or three days.

Of course, even so, Yoruichi still didn't let him off the hook.

Yoruichi's original words were, "That guy who broke the record for Shikai in Soul Society, I think he probably has no hope of breaking the record for Bankai."

Yuko wasn't particularly angry, just speechless.

……

The atmosphere in the First Squad's barracks was heavy.

"...This concludes the summary report on the disappearances of souls in Rukongai over the past month." Chojiro Sasakibe, holding a document in his hand, finished his report, bowed, and stepped aside.

Captain-General Yamamoto Genryusai Shigekuni closed his eyes and remained silent, rhythmically tapping the armrest with his index finger.

After a long pause, he calmly said, "Order the Ninth Division to go and investigate the truth of the incident."

"Understood." Chojiro bowed slightly and then withdrew.

……

The inner world of Ikuko.

"How is it? Delicious, right?" Yuko looked at Butterfly sitting on the veranda with anticipation.

The butterfly with a horn on its head exclaimed in praise, "Mmm! It's delicious! This is the first time I've ever eaten anything like this, no, the first time I've ever tasted food."

"Well, since I've been so good to you, can you tell me now?" Yuko stroked her hair. "You don't want me to keep being mocked by Yoruichi, do you?"

Fortunately, I could still find the kitchen in this inner world, otherwise I really wouldn't know what to do.

"Even though I rarely use my Zanpakuto myself, it keeps chasing after me."

With food in its mouth, the butterfly turned to look at Yuko and mumbled, "Can I spit it out now?"

Yu Zi's lips twitched violently twice: "Never mind, forget I asked."

Upon hearing this, Butterfly swallowed her food and breathed a sigh of relief: "Phew~ I almost ended up being begging for food."

"That's a bit much," Yu Zi rolled her eyes. "Is that how you see me?"

A hint of confusion flashed in Butterfly's eyes: "But what you just did...?"

"Don't you understand me? I was just saying it casually."

"……All right."

Yuko sighed, leaned on Butterfly's shoulder, and silently gazed at the clear sky.

Wow, that's amazing! Even though it's just my inner world, my senses are so clear. The sunlight feels just like the real thing.

Letting Yuko lean on his shoulder, Butterfly quietly ate his food.

Suddenly, Yuko turned her head away and straightened her posture: "You really don't plan to tell me?"

Even though I've already begged you so hard?

Butterfly paused in her action of holding the spoon, biting the spoon and turning her head with a puzzled look. Then, seeing Yuko's depressed expression, she couldn't help but laugh out loud.

"It's not that I don't want to tell you, but Yuko, you simply don't understand my abilities."

"What ability?" Yu Zi frowned.

Isn't it an ability related to space?

Even with Bankai, the changes shouldn't be too drastic.

The butterfly tilted its head: "Guess?"

Yuko's eyes widened: "Just tell me and I'll understand!"

The butterfly crossed its arms: "No, this is the only point you need to figure out for yourself."

Just as Yuko was sighing and thinking that she probably wouldn't have a chance this time, she heard Butterfly suddenly say something.

"However, I can remind you of something."

Yu Zi chuckled: "Five characters? And it even includes the character for 'butterfly'?"

"So that's what Yuko thinks. Well, never mind then." Butterfly paused for a moment, then lowered her head and started eating.

"I admit I was wrong, you're so magnanimous." Yu Zi grabbed the spoon.

The butterfly looked up with a smile: "The hint is that it's related to the name."

"Name? What name?"

Yuko wanted to ask something more, but suddenly her vision blurred and the butterfly's face became indistinct.

"See you next time~" Butterfly smiled and waved to Yuko.

"Wait……"

Yuko awoke from her meditation, her legs resting on her Zanpakuto, which emitted a dark purple light.

"Do you need to tell me! Of course I know it's related to the name!" Yu Zilai shook the blade angrily.

Isn't this just nonsense literature?!

The butterfly did not respond.

Yu Zi sighed, and seeing that there was really no other way, she got up, pushed open the door, and went out.

In the courtyard, Yoruichi was looking down at the intelligence report in her hand with a serious expression.

Yuko asked curiously, "What happened? Why are you so serious?"

Yoru glanced at him and asked, "Have you heard about the recent disappearances of souls in Rukongai?"

"The soul is missing?" Yuko frowned and thought carefully. "It seems... when I was strolling around Rukongai with Aya, I heard a couple of things from other people."

"Is there anything strange?"

It's perfectly normal for a few souls to go missing in Rukongai; they might just have been eaten by some Hollow that wandered over there.

Having probably guessed what Yuuko was thinking, Yoruichi shook her head: "It's different from that."

"If one becomes a spirit particle due to death, the clothes on their body will also disappear."

Yuko narrowed her eyes slightly: "So that means..."

"It wasn't death, but rather an inexplicable inability to maintain human form, and they just disappeared." Yoruichi waved the documents in her hand. "That's what Captain Unohana said in the intelligence report."

"The entire Ninth Division is now on the move, led by Captain Kensei Muguruma and Vice Captain Shiro Kugane."

Yu Zi nodded slightly: "It seems that the old man also cares about this matter quite a bit."

"Well, hopefully things will go smoothly."

……

night.

"Yuko, do you want to do some exercise after dinner?" Yoruichi put down her chopsticks. "Recently, I've had some new insights into the development of Shunko, and I can now combine Hakuda and Kido to a more stable degree."

Remembering what Butterfly had said earlier, Yuko replied without hesitation, "Sure."

"I was just thinking of researching Bankai, and what Butterfly said is making me a little curious."

"Then I'll leave the dishwashing to Yushiro."

“…I understand.” Yushiro thought to himself, what does “I’m leaving it to you” mean?

It's not like you've washed it before!

He's always been the one washing the dishes, okay?!

My sister is clearly just eating and drinking for free.

"Let's go..."

"Emergency situation!!!"

Suddenly, a series of deafening shouts of assemblies came from outside the mansion.

"Emergency mobilization!!"

"Emergency mobilization!!!"

"All captains, please assemble at the First Division barracks immediately!!!"

Then it gradually disappeared into the distance.

Ye Yi's expression changed slightly, and he suddenly stood up: "It seems something has happened."

Yuko looked outside and said instinctively, "This is the first time I've heard this noise. Could it be that the entire Ninth Division has been wiped out?"

This situation didn't occur even when the vice-captain was seriously injured before, and the Ninth Division mobilized almost its entire force, with the captain and vice-captain leading the team. There seems to be no other speculation, right?

"Who knows? I'm not optimistic about it." Yoruichi quickly put on her captain's haori. "Ikuko, I'll leave the defense of the base to you."

Yu Zi shrugged and waved her hand casually: "Don't worry, take your time."

"Don't make it sound like I'm going to my death!" Yoruichi retorted, and before Yuuko could retort, she vanished from their sight with a flash.

Yushiro sighed, "I hope everything goes well."

He is too weak to share the burden with his sister.

Yushiro could roughly understand why Kuchiki Byakuya was so desperate to become stronger.

He also wanted to be his sister's pillar of support.

Yuko gazed at the spot where Yoruichi had left, a strange sense of foreboding rising within her.

This premonition came without reason, but it felt as if a large hand had grabbed her heart, making her feel somewhat uncomfortable.