Chapter Text
"So, you've been waiting for us?" Tanjiro asked, eyes narrowing as he studied the demon before him.
"Because I was told to bring you to her," the demon sneered.
Tanjiro remained composed, but his focus didn’t waver. "I could’ve tracked you by scent."
The demon scoffed, crossing his arms. "She’s in a place hidden by a cloaking spell. No way you’d find it on your own."
Tanjiro tilted his head slightly. "Cloaking?”
The demon's expression twisted in disgust as he pointed to Nezuko, standing silently beside her brother. "Anyway... Isn’t that girl a demon? And an eyesore to boot."
Tanjiro blinked in confusion, his mind struggling to grasp what the demon had said.
Eyesore? What does he mean by that? Does he mean ugly? Who’s ugly?
His thoughts tumbled over one another as he processed the insult. Then, realization hit him like a wave. The demon was pointing at… Nezuko?
"H-HUH?!" Tanjiro exclaimed in disbelief. His voice rose in defense, indignant. "Who in their right mind would call her an eyesore?! Just take a look at her! Her features are beautiful—she was the pride of our hometown! Our Nezuko!"
The demon blinked, clearly not expecting such an impassioned defense. After a brief moment of stunned silence, he turned his back on Tanjiro, waving dismissively.
"Let’s just go."
"Sure, we’ll go… but I’m not letting this go either!" Tanjiro continued, his voice steady with conviction as he followed. "There’s no way she’s an eyesore! Not on your life!" His grumbles carried on, echoing in the night air as they walked.
The demon led the way, but Tanjiro was relentless. "Seriously, just take a look at her when there’s more light! You’ll see!"
As they reached what appeared to be a dead end, the demon stopped, his back still turned.
"Oh! I get it!" Tanjiro perked up, suddenly fumbling with Nezuko’s muzzle. "Maybe it’s the muzzle? That’s it, right? You might not have seen her properly because of it!" His hands worked to loosen the bamboo muzzle, his determination unshaken. "I’d like you to see Nezuko without—"
Tanjiro’s words trailed off as he noticed the demon phasing through a solid wall, vanishing into the stone as if it wasn’t there. For a second, Tanjiro was frozen, mouth agape.
The demon’s head poked back out. "Hurry it up, you fool. While no one’s watching."
Regaining his composure, Tanjiro reached out hesitantly, pushing his hand against the wall. To his surprise, his fingers passed through effortlessly. He grabbed Nezuko’s hand, leading her with him through the invisible barrier.
On the other side, they found themselves in front of a small building—a pharmacy of sorts. The smell of herbs and medicines filled the air, mingling with the faint scent of blood.
"Get over here," the demon snapped, clearly irritated by Tanjiro’s earlier antics. "Listen carefully. Don’t do anything to offend her. Not if you value your life."
Tanjiro blinked, taken aback by the sudden shift in the demon’s tone. "O-Okay…"
The demon leaned in, his expression dark. "I couldn’t care less what happens to you. I only brought you here because she insisted."
Tanjiro swallowed, nodding quickly. "R-right…"
With one last threatening glare, the demon knocked on the door. The sound echoed softly in the stillness, and a moment later, a calm voice answered from inside.
"Come in."
The demon opened the door, revealing a softly lit room. Sitting beside a bed was a beautiful woman, her presence serene and otherworldly. She looked up at them, her expression gentle but reserved.
"I have returned," the demon said as he stepped inside.
"Welcome back," the woman greeted him. Her voice was as soft as a breeze.
Tanjiro’s eyes widened as he saw the woman tending to another person—a lady who lay unconscious on the bed. He quickly stepped forward, bowing respectfully. "I’m sorry to have left you with that earlier. How’s she doing?”
"She’ll recover," the woman said, glancing down at the patient. "However, I had no choice but to restrain her husband in the basement.”
Tanjiro’s brow furrowed in concern, and he hesitated before asking, "Isn’t treating human wounds unbearable for you… as a demon?"
Before the woman could reply, the demon beside him elbowed him sharply in the ribs, causing Tanjiro to wince. "Are you an idiot? You think we demons are drooling over human blood while we work?"
"S-Sorry," Tanjiro stammered, clutching his side.
"Yushiro," the woman interrupted, her tone firm but calm. "There’s no need for violence."
She turned to Tanjiro, her expression softening. "I’m sorry. I never introduced myself. My name is Tamayo, and that boy is Yushiro." She gave Yushiro a kind glance. "I hope you’ll become friends."
Tanjiro glanced toward Yushiro, who was glaring daggers at him, clearly fuming at the very suggestion of friendship. Tanjiro forced an awkward smile.
"I don’t think that’s going to happen…" he muttered to himself.
"As for your question," Tamayo continued, "it’s not unbearable for me." She stepped away from the bed and walked over to Tanjiro, her movements graceful. "I’ve modified my body significantly. It makes controlling the hunger easier. I’ve also broken Kibutsuji’s curse."
"Kibutsuji’s… curse?" Tanjiro repeated, confusion plain in his voice. "And modified your body?"
Tamayo removed her white coat, revealing a more relaxed, but still poised, demeanor. She gestured toward another door on the far side of the room. "Please, come this way. I will explain further."
...
"Nezuko! That's bad manners!" Tanjiro exclaimed as Nezuko casually laid down on the floor, her head resting against the cool surface.
"That's quite alright. Please, make yourselves at home," Tamayo reassured with a kind smile.
"Sorry," Tanjiro muttered sheepishly, scratching the back of his head.
"Now then," Tamayo continued smoothly, returning to her explanation. "As I was saying, I've adjusted our bodies so that we can live without devouring humans. A small amount of human blood is all we require."
"Blood?" Tanjiro's brow furrowed. "You mean..."
Tamayo nodded calmly. "You might find it distasteful, but I buy blood under the guise of blood donations. It's collected in small amounts, and the process is carefully regulated to ensure it’s safe for the donors."
So that’s why I didn’t smell the same strange scent I usually associate with demons on them... But they do still need human blood after all, Tanjiro thought. His mind began to churn with questions, his eyes narrowing as he considered their situation.
"Yushiro here can survive on even less blood," Tamayo added, gesturing to her companion. "That’s because I’m the one who turned him into a demon."
"You did that?" Tanjiro’s surprise was clear.
Tamayo sighed softly. "Normally, only Kibutsuji and the Twelve Moons under his control can create new demons. But after more than 200 years of research and effort, I was finally able to transform Yushiro."
"Two... hundred years..." Tanjiro blinked, the weight of that time sinking in. His jaw dropped slightly. "You managed to turn Yushiro into a demon after two centuries?! How old are you, Miss Tamayo—"
Before he could finish, Yushiro swiftly delivered a chop to Tanjiro’s stomach, causing him to sputter and double over.
"Don't ask a lady her age, you ill-mannered fool!" Yushiro snapped, glaring at him.
"Yushiro," Tamayo's voice dropped a few degrees, her aura darkening around her. "If you strike that boy again, I will make you regret it."
Yushiro immediately jumped back to his seat, practically teleporting away. "Y-Yes, Lady Tamayo! Of course!" Internally, Yushiro admired her even more. She’s beautiful even when she’s angry…
Clearing his throat, Tanjiro straightened up again, albeit cautiously. Tamayo gave him a reassuring nod. "There’s one more thing I need to clarify: I don’t want to create more demons. I only perform the transformation on the terminally ill or those so gravely injured that they have no time left. And even then, I always ask if they want to live on as a demon."
Tanjiro closed his eyes for a moment, deeply reflecting on her words. He focused, letting his senses guide him. Her scent is pure... she’s honest. There’s no deception here. She’s someone I can trust.
"...Miss Tamayo," Tanjiro said carefully, his voice filled with quiet hope, "is there a way to return a demon back to human form?"
There was a brief moment of silence before Tamayo responded. "There is a way..."
Tanjiro’s eyes widened in shock. "R-Really?! Please, teach me—"
Before he could finish, Yushiro immediately tackled him to the ground, slamming him down in one swift motion. "Don’t you dare get so close to Lady Tamayo!"
"Yushiro..." Tamayo’s voice turned cold, a dark energy radiating from her. "The next time you lay a hand on him, I’ll make you regret it."
"Y-Yes, ma'am!" Yushiro stammered, hastily getting off Tanjiro. "I-I only threw him, I didn’t hit him!"
Tanjiro sat up, wincing slightly but still determined. Tamayo, now much calmer, continued her explanation. "As I was saying, there’s always some form of treatment or aid for any affliction. However, I have not yet discovered how to fully revert a demon back into a human. But I promise I’m working on it. We're committed to finding a way."
Tanjiro nodded, determination blazing in his eyes. "What do you need me to do?"
"The first step," Tamayo began, "is to study the blood of different demons. Which brings me to two requests I have for you. First, I would like your permission to study your sister Nezuko’s blood. Her condition is unlike any other I’ve ever encountered."
Tanjiro glanced at Nezuko, who was still laying on the floor, content. "Nezuko’s… condition is really that rare?" he asked.
"Of course, you fool!" Yushiro snapped again. "Is there any other demon you know who’s kind or normal?!"
Tanjiro blinked and rubbed his chin. "Actually… yes?"
Yushiro and Tamayo both stared at him, their eyes wide with disbelief. In all their years, they had never encountered another demon like Nezuko—let alone another demon capable of resisting the bloodlust.
"Do you mind telling us more?" Tamayo asked, leaning forward with a look of curiosity.
Tanjiro nodded, gathering his thoughts. "On the day Nezuko was turned into a demon, a Demon Slayer came to kill her. But… in the end, he decided to spare her life.”
Tamayo’s eyes grew distant as she listened, her mind drifting toward a forgotten memory.
"It turned out he was a demon too… He helped me and my sister, brought us to a trainer, and even stayed to help me train to become a Demon Slayer," Tanjiro continued.
"A Demon Slayer... turned demon?" Tamayo whispered, her brows knitting together. "Is he still part of the Demon Slayer Corps? Was he accepted by them?"
Tanjiro frowned, the question tugging at his heart. "...I’m not sure.”
Tamayo frowned. It seemed that the Demon Slayer Corps haven’t changed. After all, they banished a Slayer for protecting a demon, she could only imagine how severe the punishment for both protecting a demon and becoming one was. “I see... Do you know what rank he held?"
"No… but Giyuu-san is strong. Very strong. Giyuu-san never talked much about himself. And whenever he did, I could always smell this sadness and grief coming from him… so I never asked.” Tanjiro replied earnestly.
"And he never showed any signs of aggression?" Tamayo asked.
"Never. Not once."
"How unusual..." Tamayo mused, her mind turning over the possibilities. "To go so long without blood—neither human nor animal—and yet show no signs of violence. That could be the key to unlocking a cure… Where is this Giyuu-san now?"
Tanjiro’s expression darkened with sadness. "He disappeared a few weeks ago… I don’t know where he went. But I’ll find him. I’ll find him, no matter what."
Feeling a soft touch, Tanjiro looked down to see Nezuko’s small hand gripping his. She nuzzled her head against his palm, her presence soothing.
Tamayo smiled gently at the sight before turning serious once again. "My second request is a difficult one. In order to study Kibutsuji’s blood more closely, I need samples from demons with his blood running strong in their veins—demons with powers that rival his own. It won’t be easy. Are you still willing to help?"
Tanjiro clenched his fists, looking at Nezuko and thinking of Giyuu. His voice was steady with resolve. "If that’s what it takes, then I’ll do it. If it means you can find a way to help Nezuko, Giyuu-san, and other people like them, then I’ll help in any way I can." He smiled softly. "It’s not just for my sister… it’s for everyone."
Tamayo returned his smile. "Thank you, Tanjiro. Your help will mean everything."
Seeing her, Tanjiro couldn’t help the blush that found its way into his cheeks. Yushiro immediately began glaring daggers into him. But then, Yushiro’s head snapped toward the door. His eyes widened in sudden panic.
"GET DOWN!" Yushiro yelled, just as a temari ball hurtled through the window. Tanjiro instinctively covered Nezuko with his body, while Yushiro shielded Tamayo. The temari ball ricocheted off the walls, tearing through furniture and leaving cracks in the stone.
Outside, a male voice called out. "Have you decided how to kill them?"
A shrill laugh echoed through the night. "Vindictively, of course!" A girl’s voice, high-pitched and maniacal, filled the air as she prepared to throw more temari balls.
Tanjiro gritted his teeth, his hand instinctively reaching for his sword as the room trembled under the force of the attack.
—————
A few months later...
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Rengoku’s eyes blazed with determination as he scouted out the area, his heightened senses pinpointing the target—a sprawling demon nest hidden deep in the forest. His grip tightened around his sword as he burst forward.
"Flame Breathing, First Form: Unknowing Fire!” His blade ignited in a brilliant arc of flame, slicing cleanly through the neck of the nearest demon. The demon’s head flew off, dissolving into ash before it hit the ground. But Rengoku didn’t stop. His feet barely touched the earth as he launched himself toward the next demon.
"Second Form: Rising Scorching Sun!” His blade blazed upward, cutting through the next demon with fiery precision. He continued to make quick work of the remaining demons, their bodies crumbling to dust in the wake of his searing attacks.
As the last one fell, Rengoku paused, his brow furrowing. Why have so many demon nests been appearing recently? He wiped his blade clean, scanning the area once more before moving on. The strange increase in demon activity gnawed at his instincts—something was wrong.
…
Mitsuri’s eyes widened in shock, nearly choking on her meal. "W-what? Another demon?" she asked, looking up at her crow, still holding her chopsticks mid-bite.
“Caw! Yes!” the crow confirmed, already preparing to take flight.
I didn’t even get to finish my meal… Mitsuri pouted internally, but despite her disappointment, she was on her feet in an instant. She hurriedly placed enough money on the table to cover her barely-touched food—far more than necessary—and dashed out of the restaurant with a sigh.
I can eat later… but I can’t leave people in danger. Her grip tightened on her sword as she dashed toward her next battle, her resolve firm.
…
Tengen had just dipped into the water in his private bathhouse, the steam rising lazily around him. His crow swooped in suddenly, its loud caw piercing the tranquil atmosphere.
“Caw! Urgent! Another demon threat!” it screeched.
Tengen sighed dramatically, his eyes narrowing. Just when I was about to enjoy some peace and flamboyantness… He rose from the water in one fluid motion, his twin cleavers gleaming in the soft light. He dressed quickly, securing his gear with practiced ease.
"Time to take care of this with a little flair," he muttered with a grin, dashing out of the bathhouse. Let’s make this one explosive.
…
“Wind Breathing, Fourth Form: Rising Dust Storm!” Sanemi’s voice echoed as a massive whirlwind tore through the night sky. His blade moved with terrifying speed, creating a vortex that ripped apart several demons in mid-air. Their screams were swallowed by the storm as their blood rained down like a macabre shower.
As the last demon was shredded to pieces, Sanemi sheathed his sword with a huff, his gaze hardening. "What the hell is going on… why are there so many demons recently?" His breath was steady despite the carnage, but the unease only deepened.
From above, his crow, Sorai, cawed urgently. “Caw! Caw!” It signaled a new destination, urging him forward. Clicking his tongue in frustration, Sanemi wiped the demon blood from his face and sprinted after the crow. There’s no end to this.
…
Hidden in the shadows, Obanai observed his surroundings with sharp eyes, Kaburamaru slithering quietly around his shoulders. His crow’s sudden caw broke the silence.
"Another one? Tch," he clicked his tongue. “Of course, more demons.”
Without another word, Obanai slithered away into the darkness, his movements quiet and precise. He moved like a serpent, slipping through the forest toward his next target. The demons are multiplying… but why? His unease only grew with every step.
…
Muichiro stared blankly at the sky, his mind drifting in and out of focus as the clouds lazily rolled by. His crow suddenly swooped down, cawing frantically in his ear.
“Muichiro! A demon’s nest is nearby! Hurry!”
Blinking as if waking from a dream, Muichiro stood up slowly, his usual aloofness barely wavering. “Another one?” he murmured, his voice soft. Without hesitation, he drew his blade, the familiar weight grounding him.
So many demons lately... he thought, his expression as detached as ever. With that, he moved forward, fading into a thick mist, heading toward the danger with the same distant, calm expression.
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The rhythmic sound of prayer beads sliding through Gyomei’s fingers filled the temple. His massive form knelt in prayer, his head bowed, when the familiar caw of his crow broke through the stillness.
“Gyomei! Another demon attack!” the crow cried urgently.
Gyomei rose slowly, his towering figure casting long shadows in the flickering candlelight. He gripped his massive chained weapon, his expression serene yet resolute. "The demons grow bolder..." he murmured to himself, his deep voice reverberating through the air.
With a deep breath, Gyomei stepped out of the temple. I will protect them, he thought, his resolve as immovable as the boulders on the mountain.
…
The soft evening light filtered through the windows of the Waterfall Estate as Shinobu carefully checked her supplies. The faint sound of footsteps approached, and she looked up to see Kanao standing quietly in the doorway, her expression as unreadable as ever.
Suddenly, the sound of flapping wings drew their attention upward. Shinobu’s crow, En, swooped into the room, landing gracefully on the windowsill. "Caw! Shinobu! Mission at Mount Natagumo! Suspected Demon Moon activity! Immediate departure required!"
Kanao’s own crow came a moment after, with a similar message. Shinobu’s eyebrows arched slightly at the mention of a Demon Moon. "A Demon Moon…?" She muttered under her breath, quickly shifting into action. Her fingers deftly moved as she secured her haori, her face as calm as ever, but her mind racing.
As Shinobu finished packing her medical supplies and poison, she heard familiar footsteps approaching. Her older sister, Kanae, entered the room, her gentle smile already in place. "I heard En’s message. You’re headed to Mount Natagumo?"
Shinobu nodded, glancing over at Kanao, who was also gathering her equipment. "Yes. Kanao and I have been assigned to investigate. A Demon Moon might be involved."
Kanae’s smile faltered slightly. She moved closer to Shinobu, her voice soft. "The demons have been getting bolder. Even the Hashira have been sustaining more injuries lately. Just the other day, Rengoku-san came back with a nasty wound, and Sanemi-kun’s been pushing himself too hard." She paused, a hint of concern flickering in her eyes. "And now a Demon Moon… We haven’t seen one since…” Kanae’s voice trailed off as she glanced over towards Kanao. More specifically, the haori that Kanao wore.
Shinobu tightened her grip on her katana's handle. “Yes…”
Kanae placed a gentle hand on her sister's shoulder. "I know you can handle yourself, but still… be careful, okay?” She turned her gaze to Kanao, who looked up at her quietly. "Kanao-chan, I’m trusting you to watch over Shinobu-chan as well."
Kanao nodded.
Shinobu’s lips curled into a faint smile, the warmth of her sister’s touch soothing her usual sense of urgency. "Don’t worry, Nee-san. I’ve been watching out for Kanao all this time—besides, we make a good team." She finished strapping her blade to her side, turning to her younger Tsuguko. “Kanao, ready?"
With a quiet nod, Kanao stepped forward, standing beside her mentor. Kanae watched them for a moment, her smile returning as she studied the two girls she cared for so deeply. She knew they were capable, but it didn’t stop the ever-present worry.
“Be careful, both of you,” Kanae said softly, her voice laced with affection and concern. She would go with them, but with the influx of injured slayers they couldn’t afford to have both her and Shinobu leave.
Shinobu gave her sister one last reassuring look before nodding. "We’ll return safe and sound. I promise." Her tone was light, but the weight of her words hung in the air.
With that, Shinobu and Kanao stepped out of the Waterfall Estate, the evening breeze rustling through their haoris as they made their way toward the mountains.
As they walked, Shinobu cast a glance toward the towering mountain range in the distance, her expression unreadable. A Demon Moon…
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Giyuu didn’t know how long it had been—days, weeks, maybe even months. The passage of time had lost all meaning. Every day felt the same, a monotonous cycle of wandering aimlessly through forests, villages, and remote mountains, slaying demons wherever he found them. It was all he could do to cling to a shred of his former self.
The hunger gnawed at him constantly, a dull, persistent ache he had learned to suppress, but never fully ignore.
He didn’t need rest, didn’t need sleep. His body could move tirelessly through the night, as though time itself had no hold over him. But no matter how many demons he killed, no matter how many threats he eliminated from the world, he felt no satisfaction, no sense of accomplishment. It was never enough. He mostly kept his distance from the Demon Slayers, knowing that they would see him as a threat. Only the most skilled could even detect his presence.
A sudden, sharp noise split the air, echoing through the trees. Giyuu’s eyes shot up toward the sky, narrowing in confusion. Thunder? But there were no clouds, no sign of an impending storm. The sky was as clear as it had been moments ago.
His hand instinctively moved to the hilt of his sword. That sound—it wasn’t natural. It couldn’t be.
Could it be… Thunder Breathing? The realization hit him like a splash of cold water. If it was Thunder Breathing, then there was a Demon Slayer nearby, fighting. Another surge of sound followed, this time unmistakable, like a bolt of lightning splitting the sky, but with no accompanying flash of light. It came from the direction of the mountain in the distance.
Giyuu shot forward, dashing toward the mountain.