Demon Slayer: Dragon Hashira#23/25: Upper Rank Five—Gyokko, Slaying Gyokko. Kaidō's Psychological Warfare. Transparent World, Side Story—Urokodaki's Letter. System Upgrade.

Mount Sagiri

"You haven't learned a damn thing! Nothing's become second nature! Especially the Breathing technique Master Urokodaki taught you—you just memorized it like textbook facts. Your body hasn't absorbed any of it. What the hell have you been doing for the past six months?"

"Slow, weak, immature—you're nowhere near your senpai's level. He not only created his own Breathing Style, he split a boulder twice the size of yours!"

'What?? My senpai split a rock even bigger than this?? And created his own Breathing Style??' Tanjiro's mind reeled as he picked himself up off the ground.

"Get up! Grab your sword and keep fighting!"

"Yes!"

Tanjiro rose and resumed his bout with Sabito.

Makomo watched from the sidelines, her thoughts drifting to their junior brother, Kaidō.

'I wonder how he's doing now...'

...

One Year Later

'Today's the day Tanjiro takes Final Selection on Mount Fujikasane. I already killed the Hand Demon, so he should have an easier time.' Kaidō sat crouched by the roadside, lost in thought.

'System, of all the times to upgrade—why now? And fine, upgrade if you must, but did it really need to take almost a year? I damn near forgot you existed! And you had the audacity to drain 20% of my Interdimensional Energy for the privilege!'

After swapping territories with Obanai, the system had announced it needed an upgrade—requiring 20% of his energy. He'd worked so hard to accumulate that much. But thinking about the improved benefits post-upgrade, he'd agreed. He just hadn't expected it to take nearly twelve months. The system had been so quiet he'd genuinely started forgetting it was there.

'Whatever. It's my system, and I need it to get home eventually. Time to find some stray demon to punch.' He set off toward a nearby town.

...

After entering the town and searching for a bit, he found two demons lurking in a dark alley. Talk about bad luck—they'd just been about to hunt for humans when Kaidō showed up.

"Well, well! Look at you two, out for a stroll! Perfect timing—I need a stress ball. Hehehehe!" Kaidō's smile was positively sinister.

"Water Breathing, First Form: Water Surface Slash."

A horizontal slash decapitated one demon instantly.

After taking the Breathing Affinity Pills, Water Breathing no longer rejected him, and his mastery of Dragon Breathing had deepened considerably. So Kaidō had decided to practice Water Breathing on regular demons.

After beheading the first one, he turned to the survivor. "You—"

The other demon didn't wait for him to finish. It bolted, screaming: "MOMMY, SAVE ME! I'LL NEVER EAT HUMANS AGAIN!"

"Uh... I wasn't done talking. Why are you running?? Am I really that scary?" Kaidō sighed and gave chase at a leisurely pace.

...

A Small Forest Outside Town

'Phew... ran far enough. Should've lost that Demon Slayer by now. That guy was terrifying! Better find food somewhere else—this area's not safe.' The demon was about to leave when a hand clamped down on its shoulder.

"So why exactly were you running? Am I really that scary? Also, who's your mommy?" Kaidō's voice came from directly behind.

"AHHHH—!" The demon passed out cold.

"Seriously? You fainted?? You're a demon. Way to embarrass Muzan—that effeminate piece of... wait, no, that garbage boss." Kaidō poked the demon's head with a stick, utterly unimpressed.

'Actually, hold on. Muzan creates demons and can change gender... doesn't that technically make him their mom? Shame they're not actually born. Would've been interesting to watch Muzan give birth. What a sight that'd be.'

"Whatever. Time to string you up and practice my punches! Good thing demons regenerate. Hehehehe!"

...

"Ah... ohh... urk..."

"Please, Demon Slayer sir—just kill me already! Stop hitting me! Sob sob!" The demon dangled upside-down from a tree, pleading.

"Nah, I'm not done yet! All the other demons are hiding from me—too lazy to hunt them down. Besides, you guys regenerate. I'll let you go once I've had my fill!" BAM. Another punch to the face.

"AHHHH!"

...

Infinity Castle

"Why is there still no news about the Blue Spider Lily?" A demon in a Western suit looked down at the assembled Twelve Kizuki with cold disdain. The Upper Ranks knelt on one knee, while the Lower Ranks prostrated themselves completely, not daring to breathe.

If Kaidō saw this man, he'd instantly recognize Muzan Kibutsuji.

"Oh, Muzan-sama, please don't be upset! My followers and I have been searching diligently for the Blue Spider Lily. I'm sure we'll have news very soon!" Doma's cheerful tone was infuriatingly casual.

"SHUT UP!"

A massive hand swatted Doma's head clean off. "Doma! I haven't forgotten you let that Demon Slayer escape. If it happens again, there will be consequences!"

"Understood, sir! I'll make sure of it!" Doma's head regenerated, smile never faltering.

Muzan wanted nothing more than to erase Doma permanently. But the Upper Rank Two was powerful, and his cult followers were useful for searching for the Blue Spider Lily. He swallowed his rage.

"And you Lower Ranks—I question whether you have any value at all. You'd better deliver results. Otherwise, there's no reason for Lower Ranks to exist." His gaze shifted to Lower Rank Five.

"Rui, I have high expectations for you. Don't disappoint me."

"Yes, my lord."

"Nakime, send me back."

"Yes." The biwa demon plucked a string, and Muzan vanished.

...

"Hm? It's dawn already! Wait, did I really punch him all night?" Kaidō glanced toward the mountains where sunlight was breaking through, then looked at the demon—still strung up, face beaten to a pulp.

Demons could regenerate, sure, but it burned stamina. Lower-tier demons slowed down considerably after repeated damage. This one was a perfect example.

Kaidō cut the demon down and untied the ropes. "Alright, you've got two options. First, you can just let the sun—"

Before he could finish, the demon sprinted into direct sunlight, screaming: "FREEDOM AT LAST!"

It disintegrated instantly.

Kaidō's eye twitched. "...I wasn't done talking. I didn't even hit you that hard..."

"Forget it. Time to find an inn and get some rest. Kuroha, let's go."

The crow landed on his shoulder.

...

Nightfall

After leaving town, Kaidō received an urgent message from Kuroha.

"CAW CAW! Northwest sector—demon activity detected! Multiple villagers missing! Demon Slayers sent to investigate have lost contact! Proceed immediately! CAW CAW!"

"Northwest? If memory serves, there's a wisteria crest house in that area. Better check it out."

...

Arriving in the northwest region, Kaidō located the wisteria crest house.

"Hello. I'm a Hashira from the Demon Slayer Corps, here to investigate the missing villagers and the demon slayers who lost contact."

A beautiful woman answered the door.

"Welcome, Hashira-sama. My name is Yuri Shizuka. Please, come in."

Once inside, Yuri shared all the intelligence she'd gathered.

"That's the situation, sir. But there's something strange—every family that lost someone had a peculiar pot in their home."

"A pot?" Kaidō's brow furrowed. That detail felt familiar.

'Could it be him?'

"Sir, is something wrong?"

"Nothing. Just remembered something. What about the missing demon slayers? Any intel on them?"

"I'm sorry, sir. When those slayers went to investigate, they disappeared without a trace. When others arrived at the scenes, there was no evidence left behind."

"Understood. I'll handle it from here. Thanks for the information."

"You're too kind, sir. It's my duty."

...

After leaving the wisteria house, Kaidō headed for the village.

'Only one demon uses pots—Upper Rank Five, Gyokko. Heh... this bastard better hope it's not him.'

Entering the village, he spotted a pot at the entrance.

"What the hell? Why does this look so familiar?"

As he approached to investigate, his Hyper-Awareness flared. He stopped immediately, studying the pot from a safe distance.

'I see. So that's what this is. Upper Rank Five—Gyokko. Well, well, well. In that case, let's play!' That sinister auntie smile returned.

"Oh wow, what's this? Looks pretty... unique. Who left this lying around? So inconsiderate! What a waste of... uh, artistic potential. Shame!" Kaidō performed his dramatic monologue, clearly speaking for someone's benefit.

He walked closer, stopping about two meters away. Then he discreetly pulled a Sticky Bomb from his system inventory.

Inside the pot, Upper Rank Five Gyokko was beside himself with excitement.

'This Demon Slayer called my pot beautiful! Said leaving it here was wasteful! Finally, someone who appreciates my art!'

'Wait, why did he stop? Come closer! How can I grab him from here? Oh, I know—he must be admiring my pot! Yes, that's it! In that case, I won't capture him. I'll turn him into a demon instead! Then he can appreciate my art forever! HAHAHA, I'M A GENIUS!'

If Kaidō could hear those thoughts, he'd have yanked Gyokko out and beaten him senseless.

While Gyokko fantasized about displaying his "art," Kaidō tossed the Sticky Bomb into the pot.

'Hm? What's this? Why is it sticky? Did this bastard just SPIT in my pot?? Unforgivable—AHHH!'

BOOOOOOOOOOOOOOOOOOM!

The explosion shattered the pot. The demon inside was exposed.

"Phantom Eye!"

The instant Gyokko emerged, Kaidō activated Phantom Eye. Time slowed to a crawl—Gyokko's movements reduced to a fraction of their normal speed.

"Water Breathing, Tenth Form: Constant Flux!"

Kaidō unleashed Water Breathing's strongest technique. The more rotations, the more devastating the slash—a water dragon materialized, perfect for surprise attacks. After taking the Breathing Affinity Pills, his mastery of Water Breathing had improved dramatically.

SCHLICK.

Gyokko's head flew off—but Kaidō felt no resistance. No flesh, no bone. He'd only struck Gyokko's surface form.

He'd expected this. The entire performance had been to lower Gyokko's guard before using the bomb to destroy his pot and prevent escape.

"You wretched brat! How dare you destroy my pot—my most perfect work of art! UNFORGIVABLE!"

With his pot destroyed and having molted at the moment of decapitation, Gyokko revealed his true form. Alabaster white body, yellow eyes, green lips, purple fish fins on his head. His mouth was where his eyes should be, his eyes where his mouth and forehead should be. The kanji for Upper Five was carved into his eyes.

Gyokko's true form featured webbed hands, a serpentine lower body, and scales harder than diamond covering his entire frame—yet his body remained flexible.

He possessed the "Godlike Hands," which could transform anything his fists touched into fish.

"However, since you praised my pot earlier, I'll give you one chance. Apologize for destroying it, become a demon, and help me create my art. Do that, and I'll forgive you! What do you say? Quite generous, wouldn't you agree..." Gyokko kept talking, completely full of himself.

Gyokko was cruel and arrogant, talkative and fond of mockery. He loved defying nature's laws. He considered pottery-making the highest form of art and fancied himself an unparalleled artist. His pots were sacred to him—he couldn't tolerate anyone damaging or insulting them, especially through negative critiques.

His loyalty to Muzan Kibutsuji was absolute, bordering on worship.

"So? Have you decided? Become a demon and create art with me! If Muzan-sama recognizes your talent, you might even become an Upper Rank!"

"Are you done talking?"

Kaidō lowered his fox mask over his face and pulled his greatsword from the system inventory. "Here's my answer!"

<><><><><><><><>

"You ungrateful brat! If that's how it is, then die!"

"Blood Demon Art: Killing School of Fish!"

Gyokko leaped repeatedly at incredible speed, his smooth scales making his trajectory nearly impossible to predict as he launched assault after assault.

"Dragon Breathing, Fourth Form: Coiling Dragon."

THUD THUD THUD!

Gyokko's strikes hammered against the defensive barrier with relentless percussion.

'What's wrong with this Demon Slayer?? Why can't I hit him?? What is that turtle shell thing around him?'

"Mark—activate!"

Beneath his mask, the dragon-shaped mark on Kaidō's forehead blazed crimson.

"Phantom Eye!"

With both the Demon Slayer Mark and Phantom Eye active, Kaidō carefully tracked Gyokko's attack patterns, searching for openings.

"Found you!"

"Dragon Breathing, Tenth Form: Ultimate Art—Judgment Slash!"

The instant he identified Gyokko's pattern, Kaidō unleashed his ultimate technique. He locked onto his target and suppressed every trace of his presence.

'Huh? Where'd he go?' Gyokko realized Kaidō had vanished—not just physically, but his aura had disappeared entirely.

He scanned his surroundings frantically.

SCHLICK!

SCHLICK!

Gyokko screamed as invisible strikes severed both his arms.

'Where is that damn Demon Slayer??' Terror crept into Gyokko's mind. The moment his arms were cut, he'd heard a dragon's roar—an ominous, unsettling sound that set every nerve on edge.

SCHLICK!

After the tenth and final strike of Judgment Slash, Kaidō's form materialized directly in front of Gyokko.

"So there you are, hiding like a coward. This time I'll kill you and turn you into art."

Gyokko attempted to activate his Blood Demon Art—then noticed the world had inverted.

"What's happening? Why is everything spinning? Wait, isn't that... my body?"

"I've been decapitated?? That cursed brat! You're a Hashira, aren't you?? Playing weak when you're actually strong—what a dirty trick! I'll never forgive you!" Gyokko's severed head roared with impotent fury.

"You're so damn loud! Do me a favor and hurry up and die already! What kind of nonsense—I never said I wasn't a Hashira, you moron!"

"And have you looked in a mirror lately? You're not human, you're not demon—you're an abomination! Even female ghosts would cry at the sight of you!"

"Eyes where your mouth should be, mouth where your eyes should be—why didn't you just stick them on your ass??"

"Even a Siberian Husky looks better than you! Yeah, they're dumb and destructive and tear up the house, but at least they're cute—which is infinitely better than whatever the hell you are!"

"Your pots aren't even symmetrical! And okay, fine, asymmetry can work—but they're ugly as sin! AND STINKY! And you have the audacity to call them the world's most perfect art?? You know what? Forget 'Gyokko.' You should just change your name to 'Piss Pot!'"

"If you weren't already disintegrating, I'd tie you to a tree and roast you until you were crying for mercy! Ugly-ass waste of space—get lost!"

Kaidō's verbal assault came rapid-fire without pause, ending with a powerful kick that sent Gyokko's partially dissolved head flying into the air.

If circumstances allowed, Kaidō could probably roast Gyokko for a full day and night.

When Gyokko's head hit the ground again, Kaidō delivered one final blow that completely shattered his psyche.

"Oh, right—Piss Pot, forgot to mention: a Siberian Husky is a dog. Though honestly, you're not even comparable to a dog."

"AHHHHHHHHH! You wretched Demon Slayer! Comparing me to a dog—saying I'm worse than a dog... I'll—!"

Before he could finish, his head dissolved completely.

"Phew~ that felt good. So satisfying! Oh, almost forgot—blood sample!" He quickly retrieved a collection device and inserted it into Gyokko's dissolving body.

"Finally got an Upper Rank blood sample!"

"Meow~"

Chachamaru appeared beside Kaidō. He secured the collection device in the small pouch on the cat's back and scratched behind its ears. "Thanks, little guy. Please deliver this to Lady Tamayo!"

"Meow~" Chachamaru enjoyed the affection for a moment, then departed.

"Alright, job's done! Time to head back and rest. Kuroha, let's— wait, Kuroha?" Kaidō stretched and called for his crow, only to realize the bird was missing.

"Oh for... flew back to Headquarters to announce it, didn't he?" He facepalmed. Whatever—not like it was a secret. He let it go.

...

Demon Slayer Corps Headquarters

"CAW! Dragon Hashira Ryūjin Kaidō has slain Upper Rank Five! No injuries!"

"CAW! Dragon Hashira Ryūjin Kaidō has slain Upper Rank Five! No injuries!"

"CAW CAW! Dragon Hashira Ryūjin Kaidō has slain Upper Rank Five! No injuries!"

Kuroha circled Headquarters three times, broadcasting at maximum volume before flying toward the Ubuyashiki estate.

"An Upper Rank has been slain. Well done, Kaidō—my beloved child. After a century, the stalemate has finally broken! This marks fate's turning point! Muzan Kibutsuji, we will defeat you in this generation with our own hands. You are the only stain on my family's honor."

"Kagaya, don't get too excited! Though this is wonderful news!" Amane Ubuyashiki shared his joy.

"Amane, I have a feeling—Kaidō will be the key to eliminating Muzan Kibutsuji. His appearance signals that the century-old deadlock is about to shift dramatically."

"Amane, please inform the other Hashira. Convene a meeting immediately."

"Yes, dear."

"Sakonji-san, you've raised a truly remarkable child."

...

Hearing Kuroha's announcement, Kyojuro Rengoku was thrilled. "Mm! Impressive! Young Kaidō slew an Upper Rank! Looks like I need to work harder too! Hahaha!"

"Yo, what flamboyant news! Not bad, not bad! Hahaha! Though I'm still more flamboyant than you. One day I'll flamboyantly slay an Upper Rank too!" Tengen declared.

"Namu Amida Butsu. I must train harder as well." Gyomei immediately threw himself into intense practice.

"Oh, Obanai! Did you hear? Kaidō-kun killed an Upper Rank! Amazing!" Mitsuri exclaimed excitedly.

"Yeah, he's impressive." Obanai got a nosebleed and passed out—Mitsuri had pulled him against her chest in her excitement.

"Oh no! I'm so sorry, Obanai~!"

...

Though slaying an Upper Rank should have been cause for celebration, Kaidō spent the entire journey back feeling strangely conflicted.

'Was Piss Pot—I mean Gyokko—just weak, or have I gotten that much stronger? Why was killing an Upper Rank so easy this time? Sure, he's only Upper Five, but still an Upper Rank... Wonder how this'll affect the timeline going forward? Maybe the trash boss will create a new Upper Five replacement. Or maybe things'll just follow the original plot... Whatever. No point overthinking it. I'll deal with whatever comes.'

After wrestling with these thoughts, Kaidō decided to let it go. Whatever happened next, he'd handle it when it arrived.

...

Infinity Castle

"The Infinity Castle... appearing here means an Upper Rank died??"

A demon with peach-pink hair, golden eyes, deathly pale skin covered in dark blue criminal tattoos, and blood-red nails spoke. He wore a purple-red vest with prayer beads around his ankles—Akaza, Upper Rank Three, the Battle Demon.

"Hope it was Doma who died."

"Oh my, Akaza-dono! That's so hurtful to hear!" Doma materialized behind Akaza, placing a hand on his shoulder.

"After all, I worry about you all so much!"

"Doma-sama! Long time no see!" A male and female demon greeted him.

"Yo! Been a while, Gyutaro, Daki!"

Upper Rank Six—Gyutaro & Daki.

Gyutaro was a hunched, emaciated young demon with black-and-green hair, numerous black spots covering his face and body, torso bare.

Daki appeared as a woman with long white hair, flower ornaments in her elaborate hairstyle, and floral tattoos on her left cheek and right forehead.

"Get your hand off me!" Akaza's fist shot toward Doma's head—then his arm severed.

"Akaza, you've overstepped." A figure appeared silently beside him—a swordsman with a high black ponytail and six eyes, crimson flame marks running from his left forehead down to his neck and jaw.

Upper Rank One—Kokushibo.

"Know... your... place... Akaza." Kokushibo's speech was halting and deliberate.

"Hmph. One day, I'll surpass you, Kokushibo."

"I... await... that day."

"Eek! Kokushibo-dono is terrifying!" An elderly demon with a swollen forehead, two horns, and a hannya-like face cowered in the corner.

Upper Rank Four—Hantengu.

"Master Muzan has arrived!" Nakime announced from her elevated platform.

Instantly, every Upper Rank knelt on one knee.

"Upper Rank Five is dead. There's a vacancy among the Upper Ranks."

"I want to know why—after a century of stability—an Upper Rank has been killed. And by a teenager, no less??"

"I'm starting to question whether you Upper Ranks have any value at all."

"Oh, my lord, that's not quite accurate! I've been completely loyal, diligently searching for the Blue Spider Lily!" Doma's tone remained infuriatingly casual.

"Shut your mouth! That Demon Slayer you let escape last time is the one who killed Gyokko!"

Muzan's rage at Doma's attitude was palpable.

'So it was the demon slayer Doma let escape who killed Gyokko... that makes him a powerful opponent.' Akaza's interest was piqued.

"Akaza, I know what you're thinking. But remember—finding the Blue Spider Lily is the priority."

"Yes, my lord."

"As for the demon slayer who killed Gyokko—if any of you encounter him, eliminate him. I won't tolerate any more surprises."

"Nakime, send me back."

"Yes, my lord." Nakime plucked a string on her biwa. TWANG. A door opened behind Muzan.

"Nakime... send me... back as well."

"Yes, Kokushibo-sama."

"Oh, Nakime-san, could you also—" Before Doma could finish, a door opened beneath his feet and he dropped straight into his Eternal Paradise Cult.

"Aha! Seems I'm not hated by everyone after all! And that pretty little boy... I'll definitely catch you next time. Hehehe!"

...

Mount Fujikasane—Final Selection

"Water Breathing, First Form: Water Surface Slash."

SCHLICK!

Two low-level demons disintegrated instantly.

'This is the third day already, but I still haven't learned anything about turning Nezuko back into a human from any of these demons. Wonder how Kaidō-san is doing...'

...

Ubuyashiki Estate—Hashira Meeting

"The Master has arrived."

Instantly, all nine Hashira dropped to one knee—except Kaidō, who bowed respectfully at the waist.

"Good morning, my beloved children."

"Seeing you in good health brings us all genuine joy, Master." Kaidō spoke for the group.

"Thank you, Kaidō."

"Today's meeting concerns Dragon Hashira's elimination of an Upper Rank demon. Kaidō, please explain what happened."

"The Upper Rank I killed was Upper Five—Gyokko. He was actually quite strong—not on the level of Upper Two, but still formidable. However, he talked too much and underestimated me. When he activated his Blood Demon Art, he left an opening I could exploit. Plus, my Breathing Style happened to counter his techniques effectively, which allowed me to finish him..."

Kaidō recounted the battle in detail—naturally omitting the part where he verbally destroyed Gyokko's entire existence.

If they knew he'd roasted the demon into a mental breakdown, he'd become the second most psychologically ruthless Hashira after Shinobu.

"That's everything about my encounter with the Upper Rank."

"Regarding Upper Ranks in general—my advice is to run. Not because I doubt your abilities. Against Upper Ranks Four through Six, you might stand a chance. But the top three? I'm sorry, but even three Hashira working together might not be enough to win."

Though all three top Upper Ranks died in the original story, their deaths were bizarre flukes—one died from being too ugly, one from being poisoned after overeating, another from basically lagging out at the critical moment.

"What are you trying to say, kid?" Sanemi demanded.

"No disrespect intended. I know none of you fear death. But have you considered this: Upper Ranks have incredible regeneration. Even severe injuries heal almost instantly. But Hashira only have one life. Once you die, there's no second chance. You all know better than anyone how much training and suffering it takes to become a Hashira."

"I'd rather face every Upper Rank alone, gather all their intel, and risk my own life than watch any of you die pointlessly without understanding what you're up against."

Silence descended. Even Kagaya said nothing.

It was true—training a Hashira required immense time and resources. Lower Ranks could be replaced. Upper Ranks could eventually be replaced. But a fallen Hashira? Gone forever. And demons wouldn't give them time to train replacements.

Seeing the oppressive atmosphere, Kaidō broke the silence. "That said, don't lose hope. If you can master the Transparent World, even the top three Upper Ranks aren't invincible."

"Transparent World? What's that?" The Hashira knew about Demon Slayer Marks—the dragon pattern on Kaidō's forehead was one. But Transparent World was new.

"The Transparent World allows you to perceive reality as if everything were transparent and visible. In this state, your speed, prediction ability, and evasion all improve dramatically. You can sense muscle contractions instantly, significantly boosting combat effectiveness."

"Unfortunately, while I know how to unlock the Mark, I don't know the method for Transparent World..."

That was a lie—Kaidō knew perfectly well. But if the Hashira unlocked it now, who knew what butterfly effects might ripple through the timeline? Better to wait.

"You've already done more than enough, Kaidō. Sharing what you know is an invaluable contribution to the Corps." Kagaya smiled warmly.

...

<><><><><><><><>

Kaidō's Estate

"Dragon Hashira-sama, I have a package for you. It was sent by former Water Hashira Sakonji Urokodaki-sama." A Kakushi member presented a wooden box.

"Thanks for bringing it all this way!" Kaidō smiled warmly.

"Not at all—it's an honor to serve a Hashira!" The Kakushi was genuinely thrilled. Rumors throughout the Corps described the new Dragon Hashira as friendly and approachable, treating even ordinary Kakushi with equal respect. Today confirmed it.

Back inside, Kaidō opened the box. It contained a letter and a fox mask with a red spider lily carved on the forehead—identical to his original. His previous mask had shattered during the fight with Doma, so he'd asked a Kakushi to request a replacement from Urokodaki.

He opened the letter. It was lengthy, but filled with warmth and concern.

——

Kaidō,

You are my most exceptional student after Giyu—becoming a Hashira in less than a month. I'm incredibly proud of you.

I received a letter from the Master about your encounter with Upper Rank Two. Don't blame yourself. You faced an Upper Rank demon and survived an entire night of combat. That alone is an incredible achievement.

Throughout history, Hashira who've encountered Upper Ranks rarely survive. So don't torture yourself over this. I can't bear to lose another student.

Regarding Tanjiro—the boy you and Giyu told me about—I've accepted him as my student. If he can pass my trial, I'll allow him to take Final Selection. But only if he passes.

If you meet him again, I hope you and Giyu will continue guiding him.

Tanjiro's sister is remarkable. She suppressed her desire to eat humans through sheer willpower alone, sustaining herself through sleep. She may prove crucial in the eventual battle against Muzan Kibutsuji.

Kaidō, whatever happens—don't push yourself too hard. I want both you and Giyu to survive. You are my pride and joy.

—Sakonji Urokodaki

——

Reading those words filled Kaidō with warmth. Beyond Tanjiro's family and the Demon Slayer Corps, Urokodaki truly treated him like family.

But that only made him miss home more. After all, he was just a visitor in this world.

...

That Night—A Forest Somewhere

"Hmm..." Kaidō stood with his chin in his hand, deep in thought.

Three captured low-level demons were tied to a tree—two hanging upside-down. The third had secretly broken free and was attempting to escape.

WHOOSH!

A greatsword slammed into the ground directly in front of the fleeing demon.

"Go ahead, keep running. Let's see if you're faster than my sword." Kaidō materialized in front of the terrified demon.

"Y-y-you—what do you think demon lives are??"

A vein popped on Kaidō's forehead, his eye twitching behind his mask. 'Why does that line sound so familiar?'

"What do I think demon lives are? What do you think human lives are?"

"To hell with this! I'd rather burn in sunlight or get decapitated by a normal Demon Slayer than die as your punching bag!" The demon charged at Kaidō.

"Water Breathing, First Form: Water Surface Slash."

A horizontal slash decapitated the demon instantly.

The two remaining demons trembled violently.

'This demon slayer is different from the others. Normal demon slayers just decapitate demons with their Nichirin blades. But this guy ties us up and uses us as punching bags. And the pain—even though we regenerate, we can't take it anymore! We'd rather get decapitated like that guy than endure more torture!'

After eliminating the escapee, Kaidō turned toward the two hanging demons. Cold sweat poured down their faces.

"Alright, I'll make you a deal. Answer my questions correctly, and I'll let you go. Get them wrong, and... well, bye-bye. Let's start with you." He pointed at the demon on the left.

"How many heads does a donkey have?"

"One."

"How many legs?"

"Four."

"How many hairs?"

"??!"

"Too hard? Fine, different question. How many suns are in the sky?"

"One."

"How many moons?"

"One."

"How many stars?"

"..." The demon was speechless, completely stumped.

"Too bad. You couldn't answer. Goodbye!" One swing, and the demon disintegrated.

"Your turn. I won't even ask you trick questions. Just answer one thing honestly, and I'll let you go. Deal?"

The remaining demon nodded frantically.

"How many people have you eaten?"

"Four!"

"What?? You ate ten people??"

"No—four!"

"FOURTEEN PEOPLE??"

"NO! JUST FOUR!"

"NINETY-FOUR PEOPLE??"

"..."

Whether from sheer frustration or a mental breakdown, the demon coughed up blood and passed out.

"Wait, seriously? That fragile? He actually passed out from rage?" Kaidō blinked in confusion.

The system chimed in: [Host, did a gym teacher teach you math?]

"Nah, but a math teacher taught my gym class."

(Math Teacher: "The gym teacher is sick, so I'm covering PE. That's reasonable, right?")

(Gym Teacher: "I'm not taking the blame for this.")

"Whatever. I'll put him out of his misery." One clean strike, and the unconscious demon was gone.

...

After leaving the forest, Kaidō activated his monthly draw. "System, use this month's Random Draw."

[Ding! Drawing... Draw complete!]

[Item Obtained: Collection Card x1]

[Collection Card: Place on target's forehead to seal them inside. Tear the card to release. Note: Only effective on Lower Rank demons.]

"Huh. Shame it only works on Lower Ranks. Was planning to stick it on Muzan's forehead, trap him in card form, then release him in direct sunlight. We could share some wisteria wine, get a nice tan, maybe give him a shave with a Nichirin blade... Oh well. Might come in handy later."

[Ding! System will now begin upgrading. This requires 20% Interdimensional Energy. Proceed?]

"What?? Twenty percent??"

[Proceed with upgrade?]

After thinking it over, Kaidō decided to go ahead. Post-upgrade, the system would definitely be more beneficial. As for losing 20% energy—he could earn it back through quests afterward.

"Fine. Upgrade."

[Ding! Deducting 20% Interdimensional Energy. Beginning upgrade.]

[Current Interdimensional Energy: 40%]

[During upgrade, the system will enter sleep mode. Random Draw temporarily disabled. Lifestyle Shop will remain accessible.]

Kaidō checked—sure enough, the Random Draw button had grayed out.

"At least the shop's still open. That's convenient enough."

"Mmm~" He stretched. "Time to head back to Headquarters."

...

Infinity Castle

"DAMN IT! That cursed Demon Slayer—I'll never forgive him!" Muzan's rage was palpable. And remembering that Doma had let the demon slayer escape only made his fury burn hotter.

"Nakime! Summon Doma immediately!"

"Yes, Muzan-sama."

Nakime knew exactly what was coming. She didn't dare say a word—just executed the order.