On the way to Mount Sagiri, Haku subtly probed for information about the Demon Slayer Corps.
One of the Corps members he had saved, named Ichiki, said, "Our Demon Slayer Corps has a long history. For centuries, we've fought demons in the darkness, protecting the masses!"
The other member, named Hiroshi, nodded proudly, "That's right, Kori! The reason you grew up unaware of demons is all thanks to us!"
Haku listened thoughtfully.
Learning about the Corps' origins, he mused inwardly, "I didn't expect this world to have an organization like the Demon Slayer Corps, entangled with demons for centuries. It seems my initial decision was correct—joining the Corps should make it easy to gather intelligence on demons!"
Ichiki continued, "Kori, your talent is the greatest I've ever seen. Once you master the Breathing Techniques, you'll surely become an outstanding Demon Slayer Corps swordsman!"
Haku looked puzzled, "Breathing Techniques?"
"Yes, the reason our Corps can stand against demons is the 'Breathing Techniques' that enhance physical strength and speed. Only by mastering them can you be considered a true Demon Slayer Corps swordsman!"
Ichiki, already treating Haku as a comrade, explained earnestly.
Haku asked, "So, Ichiki-senpai, you've trained in these 'Breathing Techniques' too?"
He genuinely couldn't see how Ichiki and Hiroshi, who had trained in these techniques, had enhanced their strength or speed in any noticeable way.
"Of course!"
Ichiki nodded proudly.
Hiroshi added, "No need to rush. Mount Sagiri, where we're headed, is one of our training grounds. There's a legendary senior there!"
"A legendary senior?" Haku's curiosity was piqued. "What kind of person are they?"
"Didn't I mention earlier? The strongest swordsmen in our Corps are called 'Hashiras,' and this senior not only served as the Water Hashira but also trained two Hashiras, making them one of the Corps' surviving elders. If it weren't for that incident…"
Halfway through, Ichiki realized he'd slipped and stopped.
Haku pressed, "Ichiki-senpai, you've mentioned 'that incident' a few times. What exactly happened?"
Hiroshi sighed, "Just tell him. He'll learn about it anyway once he officially joins the Corps."
Ichiki sighed as well, his mood darkening, "Two years ago, a severe rebellion occurred within our Corps, causing massive damage we still haven't recovered from."
Haku asked, "A rebellion?! Who rebelled?"
Ichiki said gravely, "The Hashiras—all of them. They betrayed us, willingly siding with demons and becoming accomplices to those bloodthirsty monsters!"
"All the Hashiras?" Haku was stunned, then asked uncertainly, "You mean the entire leadership of the Demon Slayer Corps rebelled two years ago? How could that happen?"
Shaking his head, Ichiki said helplessly, "We still haven't figured out why the Hashiras rebelled. But since then, the Hashiras who turned into demons vanished and haven't reappeared!"
"Vanished…"
Haku's mind raced, piecing things together.
The demons that invaded the shinobi world, despite all having terrifying regenerative abilities, were distinguishable upon close inspection.
For example, the 'Upper Strings' were pure demons, while the other group of swordsmen were likely the Demon Slayer Corps' Hashiras that Ichiki mentioned, who had fallen and rebelled.
"It must be the mysterious figure organizing the invasion of the shinobi world who, under some pretext, convinced the Corps' Hashiras to join the invasion. But these Hashiras were sworn enemies of demons—how could they be so easily persuaded by the mysterious figure? There must be some secret behind this!"
Haku faintly felt that this secret was likely tied to the mysterious figure's determination to invade the shinobi world.
The talkative Ichiki continued, "Fortunately, for some reason, those powerful 'Upper String' and 'Lower String' demons also disappeared, allowing our Corps to barely survive that crisis. But recently, demons have become active again, with reports of demon attacks everywhere, stretching us thin…"
Caw, caw!
Suddenly, a black crow landed on Ichiki's shoulder, squawking, "New mission! New mission!"
Ichiki and Hiroshi exchanged wry smiles.
As they had said, demons had been rampaging lately, slaughtering without restraint, leaving them no moment of peace.
Gently patting his Kasugai Crow, Ichiki said to Haku, "Kori, it looks like we can only escort you this far. But don't worry—we've already sent your information to Mount Sagiri. Once you get there, you can begin training with the Corps."
Hiroshi added, "With your talent, you'll likely become one of us soon! Work hard, and I hope we can fight side by side someday!"
Haku nodded, "Thank you for your help. I'll do my best."
Watching the two Corps members depart, Haku sorted through the intelligence he'd gathered.
Clearly.
Contrary to his initial assumptions, demons in this world hadn't taken center stage but remained hidden in the shadows, unknown to most.
At the same time, this world had an organization—the Demon Slayer Corps—that had been fighting demons for centuries!
"That swordsman… could they have been one of the Corps' Hashiras?"
For some reason, Haku's mind flashed back to the battle that destroyed the anchor point, recalling the silent swordsman who stood alone on that island.
Why did the Corps' Hashiras rebel? Who was the mysterious figure that persuaded them? Where were they hiding now? These questions could likely only be answered by joining the Demon Slayer Corps.
With this realization, Haku no longer hesitated and continued toward Mount Sagiri.
Meanwhile.
After a night of browsing in the library, Karin had gained a general understanding of this world.
Like Haku, she hadn't expected that in a world inhabited by demons, their existence would be largely unknown. She had scoured countless books, finding only fleeting mentions of demons.
"These demons are clearly man-eating monsters, so why are there so few records of them? With the strength of ordinary people in this world, there's no way they could fight demons! No, someone or some force must be covering up their existence! If I can find who's hiding these incidents, I might uncover a lead to the mysterious figure…"
Soon after, during a routine 'Jikibi' communication, Karin shared her thoughts with Shinji.