Nightingale had lied. She didn't really study the biological makeup of demons; she only knew from the story and setting that the Blue Spider Lily could allow demons to conquer sunlight. She also knew Kibutsuji Muzan had never given up searching for the Blue Spider Lily over a thousand years—creating so many demons from his own blood because he believed the more followers he had, the higher his chances of finding it.
And the absurd part? The Blue Spider Lily only bloomed under full sunlight—and only for a few of the hottest days each year.
When you think about it, isn't it only fitting that a flower capable of overcoming sunlight would bloom in the brightest sun?
You'd think that, in a thousand years, Muzan could have just asked a few human underlings to help him search. But he was far too paranoid for that. Muzan only ever truly trusted demons—those he could kill at any moment, whose thoughts he could never hide from. As for the Blue Spider Lily, he valued it so much that he told almost no one about it—perhaps only a handful of his "most trusted." Even then, Nightingale guessed, he'd never told them what it was for—afraid someone else would overcome the sun and become perfect before he did.
There's a saying: a snake that cultivates for five hundred years becomes a jiao (flood dragon); after a thousand years—shedding the flesh, becoming bone and spirit—it becomes a dragon, ascending to immortality.
But after a thousand years, how had Kibutsuji Muzan only grown more pathetic? Nightingale seriously suspected that, when he split into over 1,800 pieces to escape from Yoriichi Tsugikuni, most of his brains were lost in the 1,500 or so bits that got hacked off.
Honestly, of all the "Demon Kings" she'd read about, the protagonist Kuramitsu Merusha from that other novel was way more impressive than Muzan.
Come to think of it, hadn't she once dreamed that Muzan fought the Corpse King Longyou from "Shi Xiong"?
...
Of the three meals a day, breakfast is the most important. If you skip breakfast, you're likely to feel out of it all day.
"Whoa! This is amazing! Is it a holiday or something?"
Breakfast today had been prepared by Kochou Shinobu and Kochou Kanae. Seeing the dishes pile up on the table, Afune—who'd grown up poor—could only gape in wonder.
Terauchi Kiyo: "It's just that we have a lot of people today!"
Nakahara Sumi: "It's not just Shinobu-neesan and Kanae-neesan, there's also Afune, Tasuke, and Nightingale-neesan!"
Takada Naho: "Afune, Tasuke, you should eat lots! Kanae-neesan's cooking is the best!"
Tasuke chirped cheerfully, and the whole breakfast felt especially lively.
The three Butterfly Estate girls were energetic, clearly very close with Afune—it made Nightingale relax just a little.
Tsuyuri Kanao sat silently, smiling politely as she ate.
"So, Sensei, are you really going to look for the Blue Spider Lily?"
Shinobu had heard some of the previous night's Hashira Meeting from Kanae, especially about the Blue Spider Lily.
If there really was a chance to wipe out all demons at once, it wasn't just the Hashira who were excited—Shinobu and the entire Demon Slayer Corps would be, too.
But if they wanted to draw Kibutsuji Muzan out, they had to find the Blue Spider Lily first.
"No, I'm not going looking for it—at least not right now."
"Why not?"
Shinobu tilted her head, confused, watching Nightingale's impassive, elegant face.
"Nightingale said... it's because we're still too weak."
Kanae sighed and explained to Shinobu, "Nightingale-san says that while she herself has the power to defeat Muzan, the rest of us don't. By her estimation, even all of us Hashira together couldn't hold off the remaining Upper Moons long enough to prevent them from helping Muzan."
"Seriously? The difference is really that big?"
Shinobu's eyes went wide, turning to Kanae in shock. "Didn't you always say that it takes about three to five Hashira to stand a chance against an Upper Moon?"
"That was just a guess based on the records left by Demon Slayers who've fought Upper Moons before," Kanae replied calmly. "But now, with Nightingale—who's actually beaten Upper Moons—standing in front of us, it's her judgment we have to trust."
"Hmm... but isn't it possible that Sensei just doesn't know how strong all of you really are?"
Shinobu set her chopsticks down and grew serious. "I mean, when Wind Hashira and Serpent Hashira faced her, they weren't using their full power, right? Maybe she just misjudged?"
"Sanemi thought the same thing. He felt underestimated. So Nightingale suggested we all go all-out and attack her together..."
"And?"
"In the end, her assessment didn't change. Actually, she lowered it: instead of saying we couldn't stall all the Upper Moons, she said even together we couldn't delay just one."
At that, Shinobu's expression twisted in horror.
"Sensei, you have to be joking! That's all the Hashira! Even the strongest among us—Stone Hashira Himejima Gyomei—how could we all get crushed by a single demon?!"
But that's not just "a single demon"—it's Upper Moon One, Kokushibo.
Everyone in the Corps thought Nightingale was basing her estimate on Upper Moon Two, Dōma, but in truth, she knew the facts from having seen the original story.
If the Hashira worked together perfectly, they might stand a chance at killing an Upper Moon. But Upper Moon One, Kokushibo, was on a different level. None of the current Hashira had Demon Slayer Marks, transparent world, or the skills they'd gain by the time of the Infinity Castle arc. They'd never even trained as a team; they had no idea how to fight as one.
Not to mention, in the original story, Kokushibo held back because he wanted to turn Muichirou into a demon. Right now, Muichirou hadn't even joined the Corps—so who knew what might happen.
If she could, Nightingale would've gladly handled all the toughest enemies herself and let the others mop up the grunts...
"Ah, one more thing! Let me ask, just let me ask!"
Kanae raised her hand with a bright grin, like a schoolkid eager to speak up in class.
"Last night, Oyakata-sama asked you a question, didn't he, Nightingale...?"
Her eyes twinkled with curiosity. "I think he said... What is your relationship with the other Nightingale—the 'Angel of Crimea'?"
"The Angel of Crimea?"
"Also named Nightingale?"
Nightingale could feel several curious gazes fixed on her.
In this world, Nightingale existed too, and had only recently passed away.
Everyone Nightingale had met so far knew little of the outside world—too focused on demon-hunting to care about foreign affairs. But the Ubuyashiki family did business abroad, so Kagaya knowing of the "Angel of Crimea" was hardly a surprise.
Same name, both nurses. No wonder Kagaya had been curious enough to ask last night.
"Oyakata-sama said she was an extraordinary physician."
Kanae recalled some of Kagaya's words from the night before. "She made incredible contributions to Western medicine—devoted her whole life to healing, raised the status of nurses, founded the modern nursing profession, and created more scientific theories of care. She made the world value public health."
"That really does sound like Nightingale-neesan... She's always reminding us about hygiene, saying it's the first defense against disease."
Afune remembered Nightingale's teachings.
"With so many similarities, why couldn't they be the same person?" Shinobu looked curiously at Kanae, who just shook her head.
"Because that Nightingale-san already passed away... just at the end of last summer."
"Last year?" Afune piped up, "Come to think of it, Nightingale-neesan arrived in our village last autumn. I even asked her where she was from, but she wouldn't say."
"See! The timing matches perfectly! That's proof!" Terauchi Kiyo jumped up, convinced she'd solved the mystery. "She only pretended to die, but really came here to help us defeat Kibutsuji Muzan! I know it—she's amazing! Even terrifying demons go 'whoosh whoosh, wham wham' and get beaten in no time!"
"But your theory just doesn't work, Kiyo."
Kanae laughed dotingly, then explained, "That Nightingale-san passed away last summer, at the age of ninety. Even if she'd faked her death, she couldn't possibly appear before us looking so young."
At that, everyone turned to size up Nightingale's face.
She looked about twenty—certainly not someone in their nineties. And no nonagenarian could possibly punch out Dōma and kick Gyokko into oblivion.
In their world, "Heroic Spirits" simply didn't exist. In their logic, only demons could remain youthful and powerful at such an age—but while Nightingale's physical strength was inhuman, all evidence proved she wasn't a demon.
Nightingale could see their curiosity, but had no intention of explaining. Silence was her only answer.
"...So, you won't answer after all?"
Kanae smiled wryly when Nightingale didn't reply. "I thought you kept quiet yesterday because there were too many people. But even now, with just a few of us, you're still silent."
Nightingale only replied offhandedly: "I don't understand what you're talking about. Those odd questions have nothing to do with saving lives. I am Nightingale... and that's all there is to it."
"Afune, stop staring at us so curiously. These aren't things you should be worrying about. Let's see... No lessons for a while, all right? You've finally got friends your age, so go play with Naho and the others."
With Afune and Tasuke, she had to play both parent and teacher—but Nightingale was adapting quickly to both roles.
"Of course, you need to finish your breakfast first. You're so busy feeding Tasuke porridge that you've hardly eaten. Cold food slows digestion, and can cause stomachaches or diarrhea. You need to watch out for that in the future."
"Okay~!"
Afune nodded obediently and tucked into her breakfast.
"Remember, chew your food well," Nightingale added.
"Okay~!"
She'd hoped she might finally learn a bit more about Nightingale-neesan... but was brushed off again.
Still, Afune didn't come away empty-handed. At least she'd found a clue—the legendary Western nurse, Nightingale. If she really wanted to pursue medicine, there'd be plenty of chances to learn about that other Nightingale in the future.
I just want to understand her better—to get closer to the person I admire. What's wrong with that?
Afune thought to herself.
After breakfast, as Shinobu cleared the dishes, she saw Nightingale getting ready to head out, her enormous red travel bag in hand.
"Sensei, are you heading out?"
Shinobu glanced at the travel bag. "That's not just an after-meal stroll, is it?"
"I'm going to visit the Ubuyashiki estate."
Nightingale opened the door, explaining simply, "Just because the illness was cured doesn't mean we can relax. There's always a risk of relapse or complications. Post-op care is vital, and until I'm certain the patient's fully recovered, I won't rest."
"I see... Then—should I go with you? As your student, I should be able to help by now."
"No need. It's not surgery this time—just some simple care. I can handle it myself. Stay and look after Afune and the others. With so many children, it's too much for Kanae alone."
A strange look flickered across Nightingale's face—she really wasn't great at dealing with kids, especially the mischievous kind.
"Luckily, Afune and the rest are all well-behaved... But honestly, sometimes I worry they're too well-behaved..."
Nightingale couldn't help but feel her own thoughts were contradictory.