Demon Slayer: My breathing technique went awry after Nezuko pushed me down.

A picture suddenly popped into Tanjiro's mind.

A crisp autumn afternoon.

Two swordsmen in team uniforms were chatting by the roadside. One of them pointed to Shirakawa Yu, who was returning home in triumph in the distance, and spoke with a face full of admiration.

"Look, that's the newly appointed tenth pillar, the pillar of color!"

The other swordsman was stunned. He reflexively replied, "Pervert? Could it be... he likes to sexually harass female team members?"

The first swordsman's face turned deathly pale instantly.

"Don't talk nonsense! Arranging color pillars, are you trying to get yourself killed?"

The second swordsman was even more terrified. He clutched his backside, his voice trembling.

"What do you mean? Lord Color Pillar... he's bisexual!?"

Not far away, listening to these words, Urokodaki Sakonji knelt on a clean white square cloth.

He smiled and slowly raised the dagger.

Then, without hesitation, he stabbed himself in the abdomen!

stab-

The blood of humiliation stained the white cloth.

Tanjiro suddenly shivered.

"No !!!!"

He jumped up in fright, his voice cracking.

"Senior brother! We can't become the pillar of lust! Master will die!!!"

The sudden shout drew everyone's attention.

All the pillars turned to look at him.

Tanjiro stood there, his face flushed red, his hands still waving.

He then realized what he had shouted and froze.

"Um...I..."

This is a rambling, incoherent statement that most people can't understand.

But some people can understand it.

Kanao lowered her head, her shoulders trembling.

Shinobu Kocho was even more direct—she burst out laughing.

Faced with the surprised looks of the crowd, Butterfly smiled, her crescent-shaped eyes curving upwards, and covered her mouth with her hand as she explained softly.

"The breathing technique used by Kawabata-kun is his self-created 'Color Breathing'..."

"Color...Breathing?"

Xiaobanai paused for a moment.

Then his eyes grew brighter and brighter.

"Color pillar!?"

He suddenly raised his arm high, his voice filled with barely suppressed excitement.

"I agree! Shirakawa Yu shall become the tenth pillar!!!"

"Pfft~"

Mitsuri covered her mouth.

"Smimasai~"

Giyu Tomioka also raised his hand.

"I disagree!"

His voice rarely carried emotion.

"This concerns our master's dignity!"

Uzui Tengen tilted his head, and the diamond pendant on his forehead swayed.

"Who is your master?"

"Our master is Urokodaki Sakonji."

All the pillars collectively said "Oh".

"So you're a top student of the former Water Column!"

Tanjiro covered his face with a slap.

Senior Brother, you're driving Master to the brink of despair!

Saagiri Mountain.

cabin.

Urokodaki Sakonji was hunched over his desk, writing furiously.

After receiving Giyu's letter, he began writing this letter to Nezuko.

I wrote and revised, revised and wrote, and struggled for quite a while.

finally--

"It's finished!"

He let out a long breath, put down his pen, stretched, and bent down to pick up the private seal from the corner of the table.

"Bang!"

The short sword that was always tucked behind his waist suddenly fell down and hit the tatami mat.

Urokodaki Sakonji was stunned.

He looked down at the dagger, then looked up at the last line of the letter.

"If Nezuko eats people, I, Urokodaki Sakonji, and my disciple, Tomioka Giyuu, are willing to commit seppuku!"

The short sword lay quietly on the tatami mat, its scabbard reflecting the afternoon sunlight.

Urokodaki murmured, "Is this... an omen?"

He stared at the knife and suddenly felt a chill run down his spine.

"I have a bad feeling about this..."

After a moment, he shook his head, put away the dagger, and solemnly pressed his personal seal on the signature area.

"Even if it's an omen, I'll accept it! I'd rather commit seppuku than tarnish the name of someone who has spent half my life slaying demons!"

The rear courtyard of the headquarters.

Under the eaves.

Shirakawa Yu's face turned pale and then red.

He listened to the suppressed laughter, the snickers, and Obanai's undisguised excited shouts below, and his lips twitched.

He turned to look at Kagaya Ubuyashiki.

The other person was giving him a look that said, "Am I right?"

Although he couldn't see, the feeling of "I knew it would be like this" was overwhelming.

Shirakawa Yu sighed softly.

He raised his hand and gestured as if to say, "Let's do it your way."

Although Kagaya Ubuyashiki couldn't see, he could hear Yu Shirakawa's helpless sigh.

Supported by his two daughters, he took a step forward, faced the pillars, and put his finger to his lips.

Close your mouth, little mouth!

The area below fell completely silent...

Ubuyashiki Kagaya spoke softly.

"Everyone guessed correctly. The new tenth pillar is none other than Kawabata-kun."

He paused.

"Regarding strength, I think everyone should have no objection."

He fought the Water Pillar in a one-on-one battle, then against the Water Pillar and Insect Pillar combined, and later demonstrated overwhelming power in his battles against the Wind Pillar and Serpent Pillar.

No one present could disagree with their strength.

Kagaya Ubuyashiki nodded and continued, "On Mount Natagumo, he killed Lower Moon Five, Rui. There were no issues with the team rules."

To become a Pillar in the Demon Slayer Corps, one must either kill a certain number of demons or eliminate the Twelve Demon Moons.

Although the Upper Rank Six demons have not been eliminated by the Demon Slayer Corps in the past hundred years, the vast majority of Pillars have been promoted by killing the Lower Rank Six demons.

Therefore, Shirakawa Yu also meets the requirements for promotion.

Upon confirming that there was still no response below, Kagaya Ubuyashiki nodded and made the decision.

"Since everything meets the requirements, let's settle on the identity of the tenth pillar."

"Yes!"

All the pillars responded in unison.

"but--"

Kagaya Ubuyashiki continued.

"Kawaba-kun's tenth pillar has a different function from yours."

"Next, the Demon Slayer Corps will provide funding, and Kawaba-kun will provide the technology, to jointly establish a laboratory dedicated to the research of demons. This demon research laboratory will be fully managed by Kawaba-kun."

He tilted his head slightly.