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

Chapter 581 Yuko's Growth

This person... is indeed a bit strange...

She appears gentle and refined, yet she exudes an aura of inexplicable danger.

It had nothing to do with the spiritual pressure hidden within him. She had no evidence to prove that this person was problematic; it had merely triggered Yuuko's warning line.

She is neither a guardian of order like Captain-Commander Yamamoto, nor a pure pervert like Unohana.

Aizen Sousuke, to her, felt like a spider lurking in the darkness, weaving a giant web.

But there's no point in thinking about these things now. After all, she's new here and hasn't even memorized all the place names yet, so how could she possibly get involved in the affairs of the Grim Reaper?

However, I'll make a note of it and remind Yoruichi about it later.

Based on the information Ikuko had, Yoruichi, as the captain of the second division, didn't know much about Aizen, the vice-captain of the fifth division.

Perhaps... if we knew what kind of person the Fifth Division Captain was, we could understand Aizen's true nature more clearly.

Yuko turned the corner without making a sound, without doing anything unusual.

……

On the other side, Aizen Sousuke stood still, watching Yuuko's figure disappear around the corner. The gentle smile on his face slowly faded, replaced by a deep, thoughtful expression.

“Tsugikuni… Ikuko…” Aizen murmured the name softly.

If the first encounter was merely a chance meeting, then this one was clearly deliberate.

The spiritual pressure fluctuations that suddenly appeared at the Shihouin residence a month ago, and the spiritual pressure fluctuations of the Captain-Commander that later appeared at the First Division barracks.

Without a doubt, both of these things are related to this Ms. Yuko.

Of course, in terms of spiritual pressure alone, Ikuko was only at the threshold of captain level for Aizen, and didn't require much attention.

If this person were any other Shinigami, even a captain-level one, he probably wouldn't even give them a second glance unless it involved him.

The biggest problem with this person is that she seems to have appeared out of nowhere in Seireitei, and she is completely out of place with everyone else in every way.

Furthermore, he has close ties with Kisuke Urahara, a key figure in his plans, which is by no means a variable that can be ignored.

What is confirmed at present is that this lady had a conflict with the Captain-Commander in the First Division. Although it was just a minor fight, the fact that she was able to fight with the Captain-Commander is enough to explain the situation.

At least, it's not because of spiritual pressure fluctuations...

Unfortunately, only the captains who were present at the time know the more specific details, and even if he wanted to find out what happened back then, it would not be an easy task.

Shihōin, Unohana, Kyōraku, and the First Division Vice-Captain and Captain-Commander...

Her ability to emerge unscathed from a conflict with the captain proves that her combat prowess is at least at the captain level, and she may even have unique strengths in certain areas.

More importantly, just now...did that woman sense something?

Yuko didn't reveal anything unusual, and he didn't sense anything amiss either, but that's what Aizen thought.

That feeling of being seen through, though only for a moment, was incredibly clear. It was as if one's heartbeat, blood, and even the subtle flow of one's spiritual energy were completely seen through.

He had never experienced that feeling of unease from anyone else before.

Or is it because he cares too much?

……

In short, let's continue to observe for now.

Aizen Sousuke adjusted his glasses, turned around, and walked towards the Fifth Division.

Back at the barracks, a silver-haired boy with a fox-like smile was already waiting at the door.

"Oh my, Vice-Captain Aizen, you're finally back." Gin Ichimaru said, squinting his eyes and speaking in a slightly flippant tone.

"Gin." Aizen regained his gentle demeanor and nodded slightly. "Is there something you need?"

“It’s nothing serious,” Gin Ichimaru said with a smile, following behind him into the office. “It’s just that Captain Hirako sent over a huge pile of documents again.”

Aizen looked around and saw that his desk was piled high with documents.

"The captain is really a headache." Aizen casually mentioned while organizing the documents with a gentle smile, "By the way, Gin, Tsugikuni Ikuko, have you ever heard of that name?"

Gin Ichimaru's eyes narrowed even more, like two curved lines. "Are you referring to that distinguished guest staying at the Shihōin residence? I've heard she's an extraordinary swordsman, and even the young master of the Kuchiki family is receiving instruction from her."

"Oh?" Aizen's pen paused on the paper. "Where did Gin hear that from?"

Gin Ichimaru shrugged. "This Miss Ikuko has been going in and out of the Fourth Division and the Kuchiki family mansion all the time lately. Quite a few people in the division have been talking about her."

Aizen looked up and adjusted his glasses: "Is that so? What's your opinion, Gin?"

Gin Ichimaru narrowed his eyes: "Is there anything strange about that woman?"

"Maybe."

"Do you need me to keep an eye on things?"

"No need."

"……clear."

……

Meanwhile, Yuuko had already arrived at the Fourth Division barracks.

The Fourth Division is considered one of the more refreshing and unconventional divisions among the Gotei 13, with a perpetually pleasant herbal scent and a peaceful atmosphere.

The team members came and went, most of them wearing gentle faces.

Upon seeing Yuko, a female soldier immediately bowed respectfully: "Lady Yuko, Captain Unohana is waiting for you in the tea room."

During this time, Yuko was frequently seen entering and leaving the Fourth Division, and her relationship with Unohana Retsu was rapidly developing, to the point that the members of the Fourth Division began to gossip about her and started addressing her with respectful titles.

"Thank you for your trouble." Yu Zi smiled and nodded in acknowledgment, without offering any further explanation.

She walked through the courtyard with practiced ease and arrived at Unohana Retsu's tea room.

"Sister Hua, I'm sorry to have kept you waiting." Yu Zi pushed open the door with a hint of apology. "I was held up by Yoruichi for a while."

Retsu Unohana sat upright at the tea table, smiling gently: "You've arrived, Yuuko."

After saying that, she gestured for Yuko to sit down.

Retsu Unohana was still wearing her pristine white captain's haori, her long braids hanging down her chest, and her face adorned with her usual gentle smile.

Those deep eyes stared at Yu Zi silently for a long time. "Your aura... is more refined than before."

"It's unbelievable that you've mastered spiritual pressure to this extent in less than a month."

Yuko smiled and said, "Well, it's because of Hana-nee and Yoruichi's constant training that I was able to master it so quickly."

Unohana Retsu pushed the tea toward Yuuko, took a small sip herself, and said, "Even so, Yuuko's talent should not be underestimated."

"Perhaps it won't be long before I become the captain."

“I’m not interested at all,” Yu Zi said with a smile, shaking her head. “Besides, that old man probably wouldn’t allow it.”

Although Yuko possesses strength nearly at the captain level, Yamamoto would never allow an exception to become captain.

“That’s true.” Retsu Unohana smiled, finished her tea, and stood up. “Are you ready?”

"Okay, that's fine."

Yuko stood up and drew her Zanpakuto from her waist.

As Unohana Retsu watched her draw her sword, the smile on her lips softened, and a hint of hunger began to rise deep in her eyes.

Hey~

With a crisp clang, weapons clashed, and the two figures appeared in the open space outside the teahouse.

Clang!

The sharp, piercing sound of metal clashing against metal rang out as the weapons in the two men's hands collided time and again.

Unlike Yoruichi's training where she released spiritual pressure to fight, her training with Unohana Retsu was simply sword strike after sword strike, pure combat.

Fortunately, there wasn't much spiritual pressure overflow, so there was no need for a special training place.

"Snow Breathing - First Form: Tornado!"

Yuko launched another attack, a snow-white tornado sweeping in, the accompanying spiritual pressure precisely controlled within the snow-white storm, with little leakage.

The biting cold, as sharp as a knife, struck Unohana Retsu.

“Very good.” Retsu Unohana’s face showed a pleasant smile. Her Zanpakuto, at an unbelievable angle, struck first and accurately blocked Ikuko’s blade.

Without pausing, Yu Zi twisted her wrist, and the blade slid upwards along the opponent's blade.

The breathing technique can be switched instantly.

"Breath of Flame, Second Form: Rising Flames!"

The blade moved upwards, unleashing a spiraling, scorching slash that aimed straight for Unohana's heart.

This is a sword style completely different from Snow Breathing, fierce and domineering.

Instead of retreating, Unohana Yachiru advanced, meeting the attack head-on with a single strike. The sheer pressure of her sword forcefully cleaved the trajectory of the flames. Her swordsmanship was devoid of any frills; each strike was simple and unadorned, yet it contained the power to shatter everything in its path.

"Your sword is becoming more and more interesting to combine." Unohana said with genuine admiration as she swung her sword. "Combining those otherworldly techniques with spiritual pressure can produce such a change."

"Yes, this is all thanks to Sister Hua's guidance."

“I didn’t give you any guidance…” Retsu Unohana’s smile widened. “I just wanted to hit you.”

Yuko smiled brightly, as the flashing blades and shadows intertwined to form an impenetrable web of death.

Yuko's swordsmanship is ever-changing, and her breathing swordsmanship, imbued with spiritual pressure, has been further enhanced in her hands.

However, even Yuko, who possesses a clear understanding of the world, has to admit it.

Even though they are both melee-type enemies like Yoruichi, Retsu Unohana and Yoruichi are completely unequal opponents.

It wasn't just because Yoruichi couldn't bear to hurt her and therefore held back, but also because Retsu Unohana's combat abilities far surpassed Yoruichi's at the moment.

Whether it's spiritual pressure or anything else.

Even though Yuko could see through her movements, the overwhelming power and flawless swordsmanship still put Yuko on the defensive.

puff!

In a moment of carelessness, Unohana Retsu's blade tore open Ikuko's left shoulder, leaving a deep wound that exposed the bone.

The excruciating pain shot through her, but Yuko's expression remained unchanged, and she didn't even notice the gushing blood.

As expected, under Unohana Retsu's keenly watched gaze, the gruesome wound healed at a visible speed, returning to its original state in just one or two breaths, without leaving a single scar.

“This ability to be immortal is something that brings joy no matter how many times I see it.” Unohana’s smile grew even brighter, a pure joy like that of a child who has found the perfect toy. “Now I can… kill you without any qualms.”

Yu Zi laughed along: "Sister Hua always scares people like this. If you just want to find a monster with super-fast regeneration, why not just find those Void creatures?"

Clang!

The blades clashed, sparks flying.

Unohana Retsu's figure drew closer, almost touching Ikuko's face, her face still splattered with Ikuko's blood.

"Xu Ke can't satisfy me like Yu Zi does."

Unohana Retsu smiled slightly: "Aren't you planning to use the second sword?"

With a flick of her wrist, Yuko turned the hilt of her Zanpakuto across the back of her hand, and with a backhand strike, forced Unohana Retsu back, leaving a scratch on her haori.

Yu Zi casually twirled her sword: "No, I'm not quite proficient in combining sword techniques yet. Let Sister Hua show me later."

Unohana Retsu lowered her eyes slightly and looked at the sword marks on her haori.

Is the difference in spiritual pressure catching up soon?

Although neither of them used much spiritual power in their battle, the difference in how spiritual power was applied to their bodies still existed.

In terms of swordsmanship alone, Yuko is no worse than her, which is one of the reasons why she is attracted to her.

but……

"Shall we continue?" Seeing that Retsu Unohana seemed a little lost in thought, Ikuko asked subconsciously, having already rearranged her stance.

Retsu Unohana withdrew her gaze from the clothes and shook her head: "No, let's stop here for today."

"Huh?" Yu Zi's momentum faltered.

This hasn't even started yet, has it?

how……

“I’m very satisfied with the training lately.” Retsu Unohana slowly sheathed her Zanpakuto. “However, Yuuko’s growth step by step has reached a point where I can no longer ignore it.”

"Let's end the training here."

"Because, if it were... no, if it were the current Yuko, I might really be unable to resist wanting to kill you."

Yuko's lips twitched, and sheathed her Zanpakuto: "No... could you please not make it sound so scary?"

"Besides, you clearly already chopped it, didn't you?"

Retsu Unohana tilted her head: "Is it scary? But Yuuko can have more babies whenever she wants, right?"

"Even if I get slashed, it's okay, right?"

Yuko was speechless: "But it would hurt a lot if I got slashed."

"Then just take it as a joke." Unohana Retsu's smile suddenly appeared. "Would you like to continue drinking tea?"

Yuko suddenly asked, "Don't you need it anymore?"

"……Um."

"I understand." Yu Zi closed her eyes. "Thank you for your guidance during this time."

Unohana Retsu shook her head slightly: "I didn't give you any guidance..."

She wasn't lying; from the very beginning, she wasn't fighting with the intention of guiding Yuko.

Whether it's the use of spiritual pressure or its combination with sword techniques, it's all something Ikuko figured out on her own.

She was only doing this to satisfy her own selfish desires.

As for why it suddenly stopped...

Unohana Retsu subconsciously touched the scar that should have been there on her chest...

Yuko accidentally cured him... I should have known better than to tease her in the first place...

She could no longer fight with Yuuko with a playful or lighthearted attitude.

She was afraid that if things continued like this, she would forget her promise to that boy.