One Piece: With Sign-in System

"Hah… hah… hah…"

All seven Hashira lay sprawled across the ground, breath ragged, their bodies soaked in sweat, as if they'd been through a hellish war.

Yet, it had only been five minutes since the battle began.

In the center of the shattered training ground, Ron stood tall. His clothes were untouched, his sword now sheathed with calm finality.

"Same time tomorrow."

Leaving those simple words behind, his figure blurred—and vanished without a trace.

Once he disappeared—

Gotou finally snapped out of his stupor and dashed into the battlefield.

"Everyone—are you alright?!"

No one responded.

Only the heavy sound of breathing could be heard—each Hashira straining to recover with their Breathing Techniques.

Mitsuri Kanroji, slumped against a tree, struggled to lift her head. She gave a weak smile toward Gotou and said, "Um… could you bring us something to eat and drink…?"

Gotou blinked for a second, then quickly understood.

"Y-Yes! Right away!"

Once he ran off—

"Are we… really this weak?" Tengen Uzui muttered. He was half-kneeling, clutching his injured left arm.

Muichiro Tokito lay flat on his back in a large crater, his blade still in hand. His usual blank expression remained, but his eyes stared at the sky. "I can't even move a single finger…"

Kyojuro Rengoku, his body covered in sword wounds, leaned on a tree and slowly pulled himself up, forcing a bright, cheerful grin despite the pain. "He is… truly unbelievable…"

His Nichirin blade had been flung far away—embedded deep in the trunk of a tree across the field.

"It's not that we're weak…" Sanemi Shinazugawa gritted out through clenched teeth, lying on his side. "That guy's swordsmanship is just too strong! Is he even human?!"

"Shinazugawa, let's not be rude to Ron," Shinobu Kocho said with a gentle smile. "Surely you haven't forgotten what happened last time you tried to question him?"

Sanemi's face paled slightly at the memory.

"It's been a long time since I fought with everything I had," Obanai Iguro murmured, slowly bending to pick up his fallen Nichirin blade. "It felt… just like a battle to the death with a demon."

He took a shaky breath and looked toward the others. "Facing Ron's sword… I feel like I can grow stronger. You feel it too, don't you?"

"Yes! Absolutely!" Mitsuri's eyes sparkled. "It's like my blood is boiling! My body's all hot, and even my sword feels like it's heating up!"

"Now that you mention it…" Tengen looked down at the twin blades in his hands. "I feel it too."

Rengoku, Sanemi, and Muichiro all fell into thoughtful silence—clearly, they had felt it as well.

…

Over the next few days, the Hashira and the five young demon slayers—including Tanjiro—underwent Ron's brutal and intensive training regimen. The results were staggering.

On the third day, both Rengoku and Sanemi awakened their Crimson Blades under the immense pressure.

On the fourth day, Mitsuri, Tengen, Muichiro, and Obanai also achieved Crimson Blade activation.

That same day, under Ron's relentless sword pressure, Muichiro Tokito—standing on the edge of life and death—regained the memories he had long lost. With his soul ignited, he completed the path of his own sword and unleashed a new, original technique. His mastery soared.

On the fifth day, Shinobu Kocho finally broke through the invisible wall that had held her back, stepping into the elusive realm of the Transparent World. At the same time, Rengoku perfected his personal Flame Breathing technique, reaching toward the ultimate peaks of both the Transparent World and the Demon Slayer Mark.

That same day, Tanjiro too completed all twelve forms of the Hinokami Kagura—perfecting the legendary Dance.

Zenitsu, Inosuke, and the others showed dramatic improvements as well.

And then—on the sixth day—

The Stone Hashira, Gyomei Himejima, and the Water Hashira, Giyu Tomioka, returned to the Demon Slayer Corps headquarters with urgent news.

Demons had begun appearing all across Japan.

And these appearances weren't random.

It was a deliberate hunt—led by the Upper Moons, targeting Demon Slayer squads across the country.

On their journey back, Gyomei and Giyu had encountered Upper Moon Five: Gyokko—

And they'd fought him.

The result: Giyu Tomioka sustained minor injuries—while Gyokko, Upper Moon Five, was heavily wounded and forced to flee.

Outside the Ubuyashiki Estate—

Ubuyashiki Kagaya had summoned all the Hashira. After listening to the full report from Giyu Tomioka and Gyomei Himejima, the atmosphere among the pillars turned grim.

"Upper Moon Five, huh…" Shinobu Kocho furrowed her brows. "Even with both Tomioka-san and Himejima-san, they couldn't finish him off. The Upper Moons really are on another level."

Tokito Muichiro, his face unreadable as ever, murmured, "Still… at least we've seen what he's capable of. We won't be caught off guard next time."

"The bigger problem," Obanai Iguro added, his tone low and serious, "is the coordinated demon assaults. With the Upper Moons leading the demons in these hunts, the average demon slayer won't be able to hold their ground."

"But this might be just the opportunity we need!" Sanemi Shinazugawa growled, punching his palm. His bloodshot eyes gleamed with savage resolve. "We take out the Upper Moons and force Muzan out of hiding!"

Kyojuro Rengoku turned to face Ubuyashiki, his voice booming with his usual passion.

"Master, what would you have us do?"

All eyes turned toward Ubuyashiki Kagaya, who had remained silent the entire time.

He stood with his head bowed, eyes closed in deep contemplation.

A long pause.

Then slowly, he lifted his head, and his calm gaze landed on Shinobu Kocho.

"Shinobu," he asked quietly, "what Ron said before… is it true?"

Shinobu blinked.

"That?" she echoed.

The other Hashira looked at one another, confused.

"What's he talking about?"

"What did Ron say?"

Under their questioning stares, the ever-composed Shinobu simply nodded to Ubuyashiki with a soft smile. "If Ron said he could do it… then he definitely can."

A small smile blossomed on Ubuyashiki's face.

"Then there's no problem."

He rose from his seat and turned to one of the Hidden Corps members stationed in the distance.

"Relay my orders. All active squads still out in the field—bring them back to HQ."

"Y-Yes, sir!"

All the Hashira—except Shinobu—were caught off guard.

"Lord Ubuyashiki… what does this mean?" Tengen asked, frowning.

Ubuyashiki turned to face them all, his voice gentle, but laced with a deeper, stirring conviction.

"My dear children… the ripples of change have begun to spread. The moment we've waited for all these years is drawing near."

"The final battle…"

He looked toward the horizon, and his tone dropped ever so slightly.

"The decisive confrontation with Muzan Kibutsuji."

A sharp intake of breath rippled through the Hashira.

Their eyes widened, hearts stirred.

And then—

As Ubuyashiki continued to speak, the weight of his words settled upon them like the silence before a great storm.

Their expressions grew solemn.

One by one, the Hashira understood.

The endgame was beginning.