Starting with Demon Slayer, Forging the Strongest Demon Blade!

As the words fell.

The sound of a biwa came from behind.

Enmu, who had fallen to the ground, was also transported out of the shifting Infinity Castle and landed on an empty street in the night.

Enmu lay there, sensing the memories carried through his blood—information about Tanjiro and everything that had been gathered.

A pained smile spread across his face.

"To receive your approval and be sent to kill this demon slayer... it's like a dream..."

Meanwhile, within Infinity Castle.

Muzan summoned the Upper Ranks of the Twelve Kizuki once more!

That demon slayer who was suspected of being possessed by Yoriichi Tsugikuni's ghost was absolutely not someone Enmu could kill. The only reason Muzan had given him blood—

Was because Enmu was merely one of many pieces of bait. To kill that monster, at the very least, an Upper Rank would have to do it!

But if even an Upper Rank could not do it, then Muzan would abandon the hunt for Tanjiro.

As for what to do about a dead Upper Rank?

When the strings of an instrument snapped, didn't one simply replace them? As long as Muzan, the master, remained, that was enough!

Elsewhere.

Demon Slayer Corps Headquarters.

Butterfly Mansion.

After fighting Sanemi Shinazugawa, the three of them had returned here and continued training in the courtyard.

But during a break.

Tanjiro sat in the corridor, eating rice balls. Three girls sat kneeling beside him, and one of them asked in a crisp voice.

"Um... Mr. Tanjiro, are you using Total Concentration Breathing twenty-four hours a day now?"

The three girls watched him curiously.

Tanjiro glanced at Ashura Maru at his waist, then turned to the three of them with a gentle smile. "Thanks to Ashura Maru, I can now maintain Total Concentration Breathing all the time."

"That's amazing..."

The three girls' faces were also full of curiosity as they looked at Ashura Maru.

One of them even asked.

"Then, Mr. Tanjiro, would you like to try blowing up a gourd?" As she spoke, she took out a small gourd and placed it directly on the corridor in front of him.

Tanjiro took a bite of his rice ball and asked with a smile.

"Do I have to make the gourd produce a sound?"

"No, you need to blow the gourd apart." The girl's voice was crisp and pleasant, but her words were genuinely rather terrifying.

"Blow it apart?"

Tanjiro picked up the gourd and tapped it, producing a dull knocking sound. It was obviously far harder than an ordinary gourd.

"That's right. The gourd Miss Kanao can blow apart now is an even bigger one." As she spoke, the three girls carried out another gourd.

It was almost as tall as he was!

"Would you like to try?"

The three girls continued asking.

When Tanjiro thought about how such a slender girl could blow apart that gourd, he found it a little frightening.

Just as he was wondering whether he should try.

Ashura Maru's voice sounded in his mind.

"This gourd poses no challenge to you. You have already perfectly mastered Constant Total Concentration. What you need now is to hone your combat skills and become proficient in the Dance of the Fire God.

"Besides that, you need to learn more Breathing Styles, integrate them, and combine them together!"

Hearing that, Tanjiro understood Ashura Maru's good intentions and answered earnestly, "Thank you for your guidance, Ashura Maru. I'll work even harder!"

As he spoke, he stood and walked toward the large gourd before the three girls, asking.

"Can I give it a try?"

"Of course."

The three girls answered in unison.

Zenitsu and Inosuke, who had been training like mad in the distance, also stopped and looked over curiously.

Then the two of them watched as Tanjiro forcibly blew apart that enormous gourd. Fragments flew everywhere.

Amid Tanjiro's apologies.

The two fell silent.

"This is bad. It feels like he's completely left us behind!" Zenitsu's eyes widened. He had known this would happen, yet he was still unwilling to accept it.

In contrast, Inosuke was much more blunt. "Hmph! Even without that sword helping me, I can do it too!"

With that, he began training madly.

Even Zenitsu had no choice but to temporarily cast aside his lazy nature and focus on training.

Time passed swiftly.

The next morning.

The three of them had only just gotten up, as usual.

When a man draped in a crimson cape, radiating righteousness, appeared in the room. It was the Flame Hashira, Kyojuro Rengoku!

"Young men, come train with me! I will do my utmost to train you. Come with me now!"

Tanjiro's nose twitched. From the scent emanating from the man, he could sense an intense sense of justice.

He was undoubtedly a good person!

"Okay!"

Neither Tanjiro nor Inosuke had any objections. Only Zenitsu rolled around on the bed, crying out, "I don't want to get beaten up anymore... Ah... nooo..."

Atone for Me with Your Death!

Amid Zenitsu's cries, the three arrived at that plain once more.

It was the same as before.

Three against one!

Kyojuro Rengoku drew the fiery red Nichirin Blade at his waist. Facing the three of them, he wore a faint smile, his gaze blazing.

"Get ready, young men. I'm coming!"

As he spoke, his aura erupted completely.

The cape behind him fluttered without wind, while heat waves rolled off his body and sparks burst forth.

But Tanjiro anxiously warned him first.

"Mr. Rengoku, Ashura Maru is too sharp. If we spar, your Nichirin Blade may be damaged."

Kyojuro Rengoku's expression did not change. He remained as righteous as ever. "Is that so, young man? But it's fine. Attack without worry!"

"Okay!"

Hearing that, Tanjiro no longer dwelled on it.

Holding his sword in both hands, he used the Dance of the Fire God. Brilliant flames blossomed across the blade!

"So this is Sun Breathing? It truly is bright and warm!" Kyojuro Rengoku laughed heartily. He had already gathered his strength and was ready to experience it for himself.

He had waited a long time for this day.

But Zenitsu and Inosuke were the ones who suffered for it.

Kyojuro Rengoku lunged forward, sword in hand, and immediately targeted Zenitsu, who had been twitching around nonstop.

"Huh? Why are you coming for me first? Don't come over here!..."

Zenitsu turned and ran.

"You really are better off asleep."

Inosuke, who stood nearby, was utterly speechless. Even he could not help complaining.

"What do you mean, asleep?"

Zenitsu turned around to ask, only to be sent flying by a punch. He hit the ground again, unable to move.

There was only one sentence in his mind now.

Why was I always the one getting hurt?

"Be careful, young man!"

Kyojuro Rengoku held back his strength, using just enough force to keep him from standing and fighting for a short while without injuring him.

Then, as usual, his body trailed flames as he charged toward Inosuke in the distance.

"You're coming for me? Why does this feel familiar somehow? Whatever, I'm not thinking about it!" Inosuke lived by one principle: if someone dared to come at him, he dared to fight. Raising his dual blades, he charged forward.

The two clashed head-on.

Inosuke unleashed one sword technique after another. In contrast, Kyojuro Rengoku did not use any sword techniques at all, only continuously using Flame Breathing.

By fighting him at close range, he was clearly honing Inosuke's combat abilities.

But it still did not last long.

Inosuke was defeated and collapsed to the ground, unable to rise again. This time, he simply gave up thinking.

He lay there without moving.

Now only Tanjiro remained. Facing Kyojuro Rengoku, he spoke with a serious expression.

"Mr. Rengoku, please instruct me!"

The two used Breathing Styles and began sparring across the plain.

All kinds of sword techniques burst forth.

Tanjiro's understanding of the Dance of the Fire God had clearly advanced further. Both his timing and power had improved.

Witnessing Tanjiro's growth firsthand, Kyojuro Rengoku felt incomparably proud. "That's it, young man! I will train you into the strongest swordsman!"

"Thank you very much for your guidance!"

Tanjiro replied with a smile as well.

Ashura Maru watched the scene from within the blade and reminded him.

"Tanjiro, take this opportunity to try using two Breathing Styles at once. Reach the point where you can switch between them freely!"

Though that was easier said than done, Tanjiro asked himself, Can I really do it? Recalling the battle at Mount Natagumo, he seemed to have done it before!

With confidence, he began to boldly try!

Tanjiro gripped his sword with both hands as flames burst from the blade. "Dance of the Fire God—Dance Flash!"

His body shot forward. He leaped into the air and spun once, Ashura Maru carrying blazing flames as it slashed down in an instant.

"A powerful strike! But too slow!"

Kyojuro Rengoku's resolute eyes stared directly at the attack. "Flame Breathing—Fourth Form—Blooming Flame Undulation!"

Holding his sword with both hands, he swung it in a winding arc before him. A vast blaze formed a swirling vortex of fire!

Tanjiro's strike was blocked.

The flames merged, but in the next instant, the blade that had been wreathed in fire suddenly erupted with a surging torrent!

"Water Breathing—Second Form—Water Wheel!"