Shuya had only one word for the Hinokami Kagura Tanjiro had just demonstrated.
Weird.
Straight-up weird.
Sun Breathing was supposed to be the strongest style in the entire Demon Slayer world. It should've looked special. Instead, watching Tanjiro go through the forms, it felt… ordinary. Almost plain.
Shuya glanced sideways at Saeko. The same mild disappointment showed on her face. She looked just as underwhelmed.
This doesn't add up, he thought.
The derivative styles—like Water Breathing—were strong enough that Tanjiro could later slice boulders bigger than himself clean in half. So why did the original look so basic?
Then it clicked.
He narrowed his eyes and watched Tanjiro more closely.
There.
He'd caught the hidden detail.
In his head, Shuya gave a quiet whistle of respect for Yoriichi Tsugikuni, the Sengoku-era swordsman who'd created this four hundred years ago. But he kept the discovery to himself for now.
He waited until Tanjiro finished the full set of forms before turning to Saeko. "Saeko-senpai, what do you think?"
"A huge letdown," she answered bluntly, shaking her head.
"Huh?" Nezuko's eyes went wide. "But… Big Sister Saeko, how can that be?"
Wasn't this supposed to be the ultimate sword style created by the strongest swordsman ever? Why was this gorgeous woman giving it such a low rating? Had her brother messed up the performance? Or had the technique changed after centuries of being passed down? If it was that weak now, could it even kill demons anymore?
"Don't worry about it," Shuya said, gently patting Nezuko's head. "The style isn't nearly as disappointing as she thinks. Honestly? From where I'm sitting, your family's Dance of the Fire God is kind of terrifying."
"Terrifying?" Saeko blinked, caught off guard.
She immediately started wondering if she'd missed something. Why else would Shuya rate something that plain so highly?
Tanjiro walked back over, curious. "Shuya-san, what do you think?"
"Mr. Kamado, could you run through it one more time?" Shuya asked. "My friend didn't catch everything clearly."
"Sure, no problem." Tanjiro headed back to the open space without hesitation.
"Saeko-senpai, watch this time," Shuya said quietly. "And use Gyo."
"Gyo?" Saeko's eyes flashed with sudden understanding. "You mean—"
"Just watch first." Shuya smiled and didn't elaborate. He ruffled Nezuko's hair lightly as they all turned back to Tanjiro.
This time Saeko did exactly as he said. She focused her Nen into her eyes and activated Gyo.
And she saw it.
As Tanjiro performed the Sun Breathing forms, a golden, flame-like aura flared around the wooden staff in his hands. A thin layer of Nen also coated his body—faint, flickering, but definitely there.
"This…" Saeko turned to Shuya, stunned.
He just nodded.
He'd suspected the Breathing Techniques couldn't be that ordinary. Then he remembered how they were described: the flashy elemental visuals in the story were just anime effects. The better the swordsman, the more they "saw" those special effects in their own mind while performing the forms.
So he'd tested it with Gyo.
Now the secret was clear.
When Tanjiro executed the forms with the exact breathing rhythm, his body was unconsciously using Nen. It was weak and instinctive—not the controlled mastery of a real Nen user—but it was real.
Shuya figured Yoriichi Tsugikuni had probably been a natural Nen user four hundred years ago. With no teacher, he'd somehow invented a system that let ordinary people tap into their life energy through breathing patterns and body movement alone.
The man was a genius.
Even with full knowledge of Nen, it had taken Shuya and the girls over a year to help Rika consciously control her aura. A technique like this would've saved her months.
It wasn't too late now.
Shuya hadn't cared much about the Breathing Styles before. But before they crossed into the real Hunter world to learn proper Nen training, this could turn out to be way more valuable than he'd thought.
"Shuya-san, should I demonstrate it again?" Tanjiro asked, not even breathing hard after two full run-throughs.
"No need. We've got it memorized," Shuya said.
"That fast?" Tanjiro looked surprised for a second, then shrugged it off. "All right. Then I'll teach you the breathing rhythm for the Dance of the Fire God."
He explained everything—the exact breathing patterns, how to sync them with the sword forms—without holding anything back from Saeko or Nezuko.
Once he was done, Tanjiro hesitated, then gathered his courage. "Shuya-san… you know so much about this. You must be someone who deals with demons, right?"
He took a breath. "If I wanted to join you… what would I need to do? I know I'm not very strong yet, but—"
"I don't want anyone else to go through what my mom and brothers did."
"I want to help stop it!!"
"Three—"
Shuya didn't answer right away. He just started counting down slowly.
"What?" Tanjiro looked confused.
"Two—!"
The second the word left his mouth, a figure in a two-toned haori stepped out of the darkness. His right hand rested casually on the hilt of the sword at his waist.
The newcomer glanced at the silver-white chains binding Kie and the boys, then his sharp gaze locked onto the most noticeable person by the campfire—Shuya.
His face stayed cold and expressionless as he asked in a low, flat voice:
"That's a heavy smell of blood. What happened here?"
"Was it a demon? Or—"
His unfriendly eyes narrowed on the silver chains in Shuya's hand.