When did you become so gentle?

The Demon Slayer Corps headquarters, infirmary.

"You're talking about the Markings?" Tsugikuni Michikatsu looked at his younger sister with surprise.

More precisely, he was looking at the red markings on his younger sister's cheeks.

They were actually somewhat similar to Yoriichi's.

Yuko nodded slightly. "I almost died at the hands of a demon back then, and it was the suddenly awakened Markings that saved my life."

"From my understanding, it seems to be an ability one can master only after their body breaks through its limits."

Tsugikuni Michikatsu stared at Yuko in shock, completely bewildered by her words.

Before Yuko, both the Demon Slayer Corps and Michikatsu himself had only regarded the markings on Yoriichi's forehead as a birthmark.

Until Yuko now also awakened Markings.

After a moment of silence, Michikatsu clenched his fist. "You said your body got stronger?"

"Mhm, I don't know the principle behind it, but I can clearly feel the improvement in my strength."

After resting for a few days, Yuko had recovered from her weakness. She could clearly feel the changes in her body.

Michikatsu abruptly stood up, gripping the hilt of the sword at his waist. "Come with me to the training grounds."

He wanted to personally verify this conjecture.

How could such an absurd thing possibly happen?

The physician beside them quickly said, "How can that be, Miss Yuko hasn't fully recovered yet."

"I think I'm already f..." Yuko said with a smile, her serene expression shifting slightly as she couldn't help but cough twice.

The physician sighed. "Your lungs suffered severe frostbite. At the current level of medical expertise, it cannot be completely eradicated. It's likely that the use of Breathing Styles will also be affected."

Michikatsu frowned. "What happened?"

Yuko shook her head. "I was just tricked by that demon."

Awakening the Markings meant not living past twenty-five.

Knowing this fact, Yuko didn't seem to care about the ailment in her lungs.

Moreover, compared to those swordsmen who died tragically at the hands of demons shortly after learning a Breathing Style, she was much, much better off.

At least, she was still alive.

It was already fortunate enough to survive after going onto the battlefield.

Seeing this, Michikatsu didn't force her further. "Then rest well."

With that, he turned to leave.

"Wait." Yuko got up from the sickbed.

The physician hurriedly tried to help her.

Yuko refused her kind offer and said, "Miss Physician, you should know my condition."

The physician paused, then sighed. "I'll find a way to deal with the problem in your lungs."

"Please try to avoid strenuous exercise."

"Thank you." Yuko smiled faintly and turned to Michikatsu. "Older Brother, let's go to the training grounds."

Michikatsu frowned as he looked at her, standing rooted to the spot.

Yuko tilted her head. "What's wrong?"

"..." After a long silence, Michikatsu abruptly spoke. "When did you become so gentle?"

It gave him a strange feeling, like the words of someone about to die.

"..." The veins on Yuko's forehead slowly emerged, and a deathly smile formed on her lips. "Oh, really? So you're the type who can't feel comfortable unless you're being scolded, Older Brother?"

"If you had said so earlier, Yuko could have sworn at you all day long."

She felt goosebumps just saying it, but as long as she could disgust Michikatsu, it was a victory.

Michikatsu ignored her this time and turned, leaving the room.

Tsugikuni Yuko took a deep breath.

Calm down, calm down.

This damned lemon-squeezer, she was going to pull a trick to bully the older one today!

The training grounds Michikatsu mentioned were not the Demon Slayer Corps' training grounds, as they were often in use there, and Michikatsu disliked being watched.

The training grounds he meant were the mountains behind the Demon Slayer Corps.

The three siblings often honed their sword skills there.

Upon arriving at the training area, Yuko set down her Nichirin Blade and reached for the wooden sword placed to the side.

"Use the real sword."

Michikatsu's voice interrupted her action. Yuko paused for a moment, then slowly drew her Nichirin Blade and stood opposite her Older Brother.

Yuko's eyes lifted slightly, looking at Kokushibo, who had also drawn his Nichirin Blade.

"Come on."

As soon as the words left her lips, two voices rang out in unison.

"Moon Breathing: First Form - Dark Moon: Evening Palace."

A iaijutsu slash, so fast that ordinary people couldn't see it, met at this moment, and the sword bodies let out a crisp, mournful cry.

Kokushibo's pupils contracted slightly, and the arm holding Yuko's Nichirin Blade trembled.

He was actually being matched in strength...

A man's body is naturally stronger than a woman's.

This was an undeniable fact.

This was also why Kokushibo didn't think highly of Yuko, even after she became a member of the Demon Slayer Corps.

He had sparred with Yuko before, and he had always defeated her easily. He had never felt such immense pressure as he did today.

She was even using a breathing style he wasn't proficient in.

It was as if she had undergone a complete transformation.

"Moon Breathing: Second Form - Pearl Flowers Floating in the Moon!"

"Water Breathing: Fourth Form - Striking Tide!"

Back and forth, Kokushibo's attacks were all blocked by Yuko.

Was it not just Yoriichi, but even Yuko was going to leave him behind?

Kokushibo's heart grew more unwilling, and the Nichirin Blade he wielded became more chaotic and disordered.

Yuko, whose physical condition had greatly improved, calmly blocked the fierce attacks from her older brother.

She wasn't stupid. Although she hadn't read the manga or learned detailed information about Tsugikuni Kokushibo.

But after twenty years together, she had long seen through Kokushibo's jealous nature.

He was constantly jealous of Yoriichi's talent. Or rather, he could accept the fact that he was inferior to others, but he could not accept that the one surpassing him was his own younger brother and sister.

Especially his twin siblings.

He was jealous of the talent that belonged to his own family.

"Cough..."

The moment Yuko's breathing became disordered due to her lung disease, Kokushibo seized an opportunity.

"Moon Breathing: Sixth Form - Perpetual Night, Solitary Moon, Endless Night!"

Several rapid crescent slashes shot towards Yuko.

The greatest strength of Moon Breathing lay in the slashes carrying more refined crescent attacks.

They could easily cover a large area.

"Hiss~"

Yuko calmly adjusted her breathing, exhaling a faint white mist.

"Snow Breathing: First Form - Blizzard!"

A white tornado, mixed with a hint of cold air, swept away all the incoming crescent slashes.

At the same time, Kokushibo, who had never witnessed Snow Breathing, was caught in the whirlwind of Yuko's sword form in his haste.

"Snow Breathing?!" Kokushibo, having lost his balance in mid-air, was shocked.

Not only in strength, but even in creating a breathing style... Doesn't this mean Yuko's talent is no different from his own?

If he couldn't even surpass his own sister, how could he possibly surpass that person!

The violent tornado continuously struck Kokushibo's body. After all, this wasn't a fight to the death; Yuko was using the blunt side of her blade.

The anxiety of defeat, coupled with the jealousy that was about to erupt, caused Kokushibo's body temperature to rise continuously, and his pulse rate also increased rapidly.

"Moon Breathing: Fifth Form - Calamitous Moon Spiral!"

Kokushibo spun in mid-air, wielding his Nichirin Blade to create a giant vortex-like blade around himself, which repelled the tornado.

The two clashed and completely canceled each other out.