Chapter 9: the twilight of the past

Michikatsu couldn't sleep. Hours had passed since the sun had set, and all the residents of the estate should have been sound asleep by now, but he couldn't. Not when it felt like his entire life had suddenly been turned upside down.

Just a few hours earlier, he had been practicing his combat technique, as he did every day to become a better swordsman. His brother had been sitting nearby, watching him train with the same curiosity he had shown for several days now. But today, the instructor their father had hired seemed to take pity on Yoriichi's interest and taught him a few basic techniques before letting him participate in a practice match.

If only he had known…

Yoriichi, in the blink of an eye, had scored four strikes: on his neck, chest, stomach, and foot, knocking him flat on his back, leaving several large bruises where he had landed his blows.

"He's a prodigy." That was all Michikatsu could think in the face of his younger brother's skill, which rivaled that of a war veteran or master swordsman.

To his surprise, Yoriichi didn't look happy or proud of what he had done. In fact, he looked even more serious than usual, as if he had just committed some terrible and unforgivable act.

"I can't stand how hitting people feels," he muttered to himself, letting the wooden katana fall from his hands before running off, shocking his older brother.

If only Michikatsu had known, he would've done anything to keep Yoriichi away from his training sessions.

Michikatsu had run after him, desperate to know why he reacted that way after discovering his combat potential. He spent several minutes searching the mansion before finally finding him sitting on the porch outside their mother's room. When he entered, he found their mother lying in bed, sleeping peacefully. Still, her pale skin and the dark circles under her eyes unsettled him. He rarely saw her, thanks to his strict training and upbringing but that didn't mean he didn't care about her.

Carefully, he sat beside her and took her hand to get a better sense of her condition. Her skin was cold and frail, her bones clearly visible through her flesh, with pronounced veins and a faint but constant tremble. He gently squeezed her hand to pass on a little warmth, while using his free hand to change the towel resting on her forehead.

"Why didn't you ever tell me anything?" he whispered.

"Mother didn't want to worry you."

Michikatsu didn't flinch at the unexpected reply. He just kept looking at her pale face, hoping to see some sign of recovery. All he found was a faint smile on her sleeping face. At least that brought him a small sense of comfort.

"Still, she should've told the servants to bring the best doctors around." The boy stood from his seat and took his place beside his brother, who looked just as serious as he had earlier.

At first, neither of them spoke, simply sitting in silence as they watched the calm evening settle in, at least, for Yoriichi. Michikatsu, on the other hand, was still troubled by his mother's condition and filled with a growing regret for not noticing her absence. From now on, he promised himself.

After a few minutes, he decided to push those thoughts aside and finally address the reason he had come in the first place. Yoriichi didn't seem interested in replying at first, but Michikatsu wasn't about to give up. He insisted on knowing the secret behind his brother's strength, whatever it was, he needed answers. How was it possible that someone with no experience could bring down a fully trained adult with such ease? Michikatsu himself hadn't even managed to land a blow on his instructor, despite training since he could remember.

"Before you go to strike, take a really deep breath. Then you take a good look at your skeletal alignment, muscle contraction, blood flow, that sort of thing," Yoriichi replied dryly.

At first, Michikatsu didn't understand what he meant. He had to think about it for a long time before reaching the conclusion that Yoriichi had some kind of ability that allowed him to see through a person's body, sensing their organs, bones, and even the flow of internal fluids. That's what enabled him to predict movements or even see them as if in slow motion.

It was a far-fetched and fictional assumption, but it was the only explanation that made any sense to Michikatsu.

But the more he thought about it, the more he realized that Yoriichi's power didn't just lie in that ability. It was also rooted in his extraordinary physical and mental capabilities. But why was Yoriichi the one gifted with such talents, and not him? They were twins, after all, practically the same in every way, except for that crimson mark that adorned his younger brother's forehead. Maybe that was what the dark red, flame-shaped mark meant a sign that set him apart from everyone else, even from Michikatsu himself.

"Brother," the younger Tsugikuni called, interrupting the older one's thoughts. "Why do you want to become a samurai?"

"Being a samurai is the greatest privilege a man can have. It proves your character, your strength, and your dedication to serving the realm and its people."

"Life is a wonderful gift, and every person has the privilege to experience unforgettable moments over time. Why waste years of it on something as cruel as fighting or hurting others?"

"Words can't solve everything. Sometimes, you have to get your hands dirty with blood so that others don't have to."

"I don't think years of suffering are worth it just for a title."

Michikatsu felt a surge of anger and indignation at his younger brother's insensitive view of such an honorable profession. Being a samurai was the highest honor a man could achieve. Few were capable of surviving the hellish training required to master the katana. Even fewer could endure years of effort, blood, sweat, and tears to perfect a combat technique. Only a rare handful were willing to study day and night to achieve the intellect and education needed not to waste the lives of the men placed under the command of a master swordsman.

And even after all that, only one or two of the dozens of apprentices across Japan ever became true samurai, those with the unshakable will and discipline to give everything on the battlefield. Wielding a sword in training was nothing like doing it in the real world. Only those with a noble desire to serve the emperor and protect the realm and its people could endure a life filled with sacrifice and death.

"How can you insult the sacrifices of so many men throughout history so coldly and emotionlessly?! Don't you understand the pain and torment people go through to become sword-wielding warriors?!" he shouted in anger, holding out his hands, bloodied and covered in wounds.

Yoriichi looked at his brother's hands with deep sadness wounds and blisters forged from years of grueling training. Carefully, he took one of Michikatsu's hands and examined it with extreme gentleness. "That must be very painful. You shouldn't hurt your body like this."

"Damn it, Yoriichi! I don't want your pity!" the older one snapped, yanking his hand away. "I just want you to help me become as strong as you, even if it takes me a lot longer. You're a prodigy, I admit that, but if we train together, we could become incredible warriors to serve the kingdom!"

Despite the outburst, Yoriichi's eyes lingered on his brother's wounds for a few seconds longer before shifting his gaze to the beauty of the sunset, now with a hint of sadness softening his expression.

"I'd rather play sugoroku or fly kites with you than talk about swords, brother."

Those words felt like a blade driving deep into Michikatsu's heart, bringing a pain greater than anything he'd ever experienced. He knew, and grudgingly accepted, that Yoriichi was far superior to him, despite having no experience. Still, he had hoped Yoriichi could at least be understanding and help him improve his training, even if he didn't want to become a master swordsman himself.

But what he received instead was what felt like cold-hearted rejection, after everything he'd endured all the punishments, the abuse just for visiting him, bringing him clothes and food, and other small comforts.

Michikatsu rose with elegance and left the area without saying a word, ignoring any reaction Yoriichi might have had. It took every ounce of willpower he had to keep from shedding the tears welling up in his eyes. He couldn't allow himself to show weakness, especially not in front of someone who had rejected him so casually.

Because despite all the rage, frustration, resentment, and most of all, the sorrow and heartbreak that Yoriichi's words had brought him, he was still a Tsugikuni. And he could not lose his composure in front of anyone.

Of course, a servant quickly informed the twins' father of what had happened. No doubt he must have been pleased and amazed by the news. It didn't even take a full day for him to change his heir. Yoriichi would now become the head of the clan, while Michikatsu was to be relegated to live as a monk, ending his dream of becoming a samurai.

The news came as a complete shock, and fear and despair flooded his mind, slowly breaking his spirit. It felt as if his very existence was worthless. His father had discarded him with brutal ease, as if all his effort and dedication to becoming a formidable warrior had meant absolutely nothing. And his brother had no intention of helping him improve.

Had Yoriichi planned all this from the beginning?

If only he had known…

"Brother?"

A soft, calm voice brought him back to reality. For a moment, he felt disoriented until he could make out Yoriichi's shadow through the doors of his quarters. He had no desire to see him right now, so he needed a few seconds to compose himself.

"…What?"

The shadowed figure shifted slightly, as if twisting in place, replacing Michikatsu's irritation with genuine curiosity at his brother's unease.

"Mother has passed," Yoriichi murmured in a hesitant tone.

Michikatsu's mind went blank again from the shock of the news. He had just seen her a few hours ago, and while she had looked fragile, he hadn't thought she was on the brink of death.

"What did you say?" He quickly got out of bed and opened the door, only to find his brother kneeling before him. He tried to convince himself this was some kind of cruel joke, but the sorrowful expression on Yoriichi's face made it impossible to believe.

"What's happened? Why would you say something like that out of the blue?"

"Forgive me," the younger brother said, bowing his head. "I beg that you hear me out and listen to my 'plot' as your retainer."

Michikatsu nodded, his brow furrowed from the news. He didn't need to be reminded of anything right now,he needed to know more about their mother and what had happened.

"I leave tonight for the temple."

Again, another statement he hadn't expected. So many unexpected revelations, paired with sleeplessness and a whirlwind of conflicting emotions, made Michikatsu's head throb painfully, barely allowing him to think straight.

"You're leaving? Now?"

Yoriichi simply nodded. "Yes. I wish only to say goodbye to you." With those words, he pulled out a small, worn piece of wood with little holes and grooves that let the wind pass through.

"A flute?" Michikatsu asked, confused.

"This flute," Yoriichi said, pointing at it with a faint smile. "I will strive, day after day. No matter how far from home I drift. I will not lose heart. Because I will think of my elder brother who gave me this flute."

Michikatsu could only stare in disbelief as his brother carefully tucked away the instrument he had made long ago, treating it as though it were a priceless treasure. He couldn't understand why Yoriichi cherished something so useless—something that couldn't even play proper notes. He should've brought something more practical, like clothes or a weapon to defend himself on the journey to the temple.

And he, as the older brother, should have been the one to give him such things. But the emotional weight he was carrying,the sadness over his future, the sudden news of their mother's death left him barely aware of what was even happening around him.

Yoriichi bowed deeply, touching his forehead to the floor before rising and walking toward the front door. Michikatsu knew he should say something too, some parting words for his brother, for the bond they shared as twins but he was still frozen, unable to react amid the overwhelming rush of emotions.

Just before disappearing into the depths of the forest, Yoriichi turned one last time and waved, his eyes reflecting the deep sadness he felt about leaving.

The last thing Michikatsu ever saw of Yoriichi Tsugikuni was his wild black hair slowly vanishing into the darkness.

Kokushibo opened his eyes just as the last memory of his brother faded,at least, what he had once believed to be the final time he would ever see him.

He still remembered how the sadness and apprehension of Yoriichi's departure had been replaced the following day by a deep, bitter mix of rage, resentment, and jealousy when he discovered that his brother had kept their mother's illness a secret for years. Years that could have been used to seek treatment, improve her condition, or perhaps even save her life. His fury had been so great in that moment that he wished Yoriichi would die or vanish on the way to the temple.

It seemed that cold-hearted wish had come true when none of the guards ever found him at the temple, and for a while, Michikatsu had been able to live in peace. That was, until years later, they crossed paths again, when Yoriichi saved him from a demon. At that moment, his fury at how strong his brother had become was only overshadowed by the sheer disbelief of seeing him wield a weapon, despite having once declared his hatred for them and by the crimson hue that now colored every strand of his hair.

500 years later, he couldn't help but feel a strange and irritating sense of nostalgia whenever he thought of him. Not that he had forgotten, on the contrary, every memory he had shared with Yoriichi remained crystal clear in his mind, as vivid as if it had happened just moments ago. A constant reminder of why he had abandoned everything, and why he clung so tightly to his mission in this new life. And yet, it had been centuries since his brother's presence in his mind stirred anything but envy and hatred, until the day he killed the last Demon Slayer who bore a black Nichirin blade.

Now, his thoughts returned to those memories in search of some clue, some answer as to why a family of humble farmers would hold knowledge and affinity toward the Breathing Style of his late brother. What did these children possess that he didn't, to be able to wield even a fraction of the power of Sun Breathing?

The bitter, nauseating scent of wisteria began to fill the air as he approached the house his master had ordered him to investigate at dusk. His brow furrowed slightly at this detail. In the memory, Muzan had sensed no trace of the flower. But now it was unmistakable incense, blossoms, and fragrances crafted from wisteria flowed on the mountain breeze.

To an ordinary demon, it would be like an impenetrable wall, but Kokushibo was not ordinary. He was Upper Moon One. His power was far too overwhelming to be bothered by mere flowers, so he continued forward, completely ignoring the foul smell.

His steps halted as he stood before the Kamado family's home. Any sign of damage or blood from the massacre had been expertly erased and restored by skilled craftsmen. The house stood in pristine condition, as though freshly built and waiting for a family to make it whole again.

When Kokushibo had witnessed his master's memories, he had been so focused on the children's appearance and abilities that he hadn't paid attention to the location where Muzan had encountered them. Now, standing before the cabin, a wave of conflicting emotions surged through every fiber of his being. He had never imagined returning to this place nor had he ever intended to, however, it seemed fate was guiding him down paths he had once walked centuries ago, back when he could still tread upon the earth beneath the sun as a human being.

Back when he walked beside his brother as Michikatsu Tsugikuni, the first Moon Hashira.

The inside of the residence was as cold as the winter forest that surrounded it. There was barely any furniture in the rooms or kitchen, some of it likely destroyed, a few pieces perhaps repaired. Inside the cupboards, there was nothing but worn-out clothes and old bedsheets, most likely belonging to the deceased owners.

There was no doubt: no one lived here. The scent of blood was barely detectable, and there was no trace of any human aroma lingering in the air. The living room was the last space in the house, just as empty as the rest though here, at least, there were a few photographs of the family placed on a small memorial shelf. Likely the only photos a poor farming family could afford, now serving as a shrine to the dead.

Kokushibo's heart stirred slightly at the sight of the photographs, specifically, the one of a man and a woman, smiling with joy on their wedding day. It was the kind of image no one would think twice about…

If not for the Hanafuda earrings and the flame-shaped mark on the man's forehead.

But that wasn't what unsettled him the most. It was the family portrait, showing the same couple older, surrounded by six children of different ages. All of them happy, sharing in the warmth of a united family despite their limited means.

The eldest son, in particular, had a mark nearly identical to his father's. Both bore the same mark that Yoriichi once carried. And to make things worse, the boy's facial features strongly resembled those of his younger brother at that age. The cheekbones weren't as pronounced, the facial structure not as sharply defined, and the eyes slightly rounder but the rest was nearly identical. Same nose, same calm smile, same wavy hair…

Combined with the affinity for Sun Breathing, it almost seemed as if these farmers were related to Yoriichi Tsugikuni.

"That can't be possible…" he muttered in his mind. He remembered the constant grief Yoriichi carried for failing his wife when she needed him most. He doubted anyone could have convinced him to move on from such a loss.

But… there had been a period of nearly sixty years in which he hadn't seen him. He couldn't say for sure that Yoriichi hadn't rebuilt his life with someone else.

Judging by the black ribbon on the wedding photo, Kokushibo could assume the father had died some time ago. But what about the eldest son? He hadn't seen him in Muzan's vision, and there was no recent trace or sign of his presence or survival.

He chose to set those thoughts aside. It was impossible these people could be Yoriichi's descendants.

By the rear courtyard, he spotted several stone structures covered with funeral decorations and wisteria flowers. Now he understood the source of the smell, someone had found the dismembered bodies and gathered them here for a proper burial.

There was only one kind of group that would do this and leave without a trace. Somehow, the Demon Slayers must have discovered a family connected to Yoriichi. Perhaps they had hoped to recruit them and instead stumbled upon a massacre.

For a moment, he considered hunting the slayers down, perhaps he might even find a Hashira but the flower's scent combined with the cold night wind had erased any human trace in the area. The snow's movement had also wiped out any footprints.

Still, something didn't quite add up. There were five graves in total, but Muzan's memory had shown six bodies. One was missing. It made no sense for the Demon Slayers to take a corpse… unless someone had survived. But he doubted that, considering the extent of the injuries they had all suffered. And even if by some miracle one of them had lived, it was impossible for them to become an active Slayer. Missing limbs and the aftereffects of such trauma would prevent them from ever using a Breathing Technique, let alone Sun Breathing.

"Unless they're after knowledge," the demon murmured thoughtfully.

That too would pose a problem for the Demon Slayers. They could gather all the knowledge they wanted, but without someone bearing Tsugikuni blood, they would never be able to revive Sun Breathing. Yoriichi had no children. The family that seemed connected to him was now dead. As for Kokushibo himself, he had two children… but had heard nothing of them after leaving his clan to become a Slayer.

Could they have found one of his own descendants?

The idea stirred a faint feeling of excitement and hope in him. He hadn't thought about his family in centuries, and so had never considered the possibility of finding one of them after all this time. But now… he was curious to know how the Tsugikuni clan had changed since his departure. If he could find a powerful swordsman carrying his blood, he might be able to train them, turn them into a demon and pass on everything he had learned through his centuries of existence. Perhaps they could even succeed where he had failed and master Sun Breathing.

His gaze lingered on the home's structure. He had already examined the place. There was no reason to stay any longer. Kokushibo had completed his task. However, there was still one thing Michikatsu had to do and as much as it bothered him to acknowledge his human side, his code of honor outweighed the disgust he felt.

Carefully, he took a bouquet of wisteria from one of the graves, along with an amulet and a few incense sticks that had been extinguished by the cold. Then he bowed in apology for his intrusion and stepped into the forest. His eyes scanned every tree nearby some were young, just reaching maturity, while others were nearing the end of their lives. A stark contrast to how they had looked when he saw them 400 years ago mere saplings, if he remembered correctly.

A faint sense of awe stirred in him when he reached his destination. A tree...nothing that would stand out to any traveler passing through these lands. But to Kokushibo, it felt like a return to his human life. Especially because the tree didn't seem to have aged a day since the last time he was here.

He brushed away the snow covering the ground until a small arrangement of weathered stones came into view. Despite the erosion, they still formed a solid and firm structure. Blue flower petals from a long-dead wild plant were scattered nearby. With his katana, he dug a small hole to anchor the amulet in the soil, along with the incense and flowers. Then, with a quick flick of his blade, he lit the sticks and knelt to recite a short prayer.

Very few times had Kokushibo felt so human again, back when life was simpler and he led the Tsugikuni clan. For the first time, he wondered what would've happened if Uta had never been killed by a demon. Perhaps Yoriichi would have never joined the Demon Slayer Corps. Maybe he would have built a family and lived in peace, growing old until death claimed him gently.

But what would have become of his own destiny?

Surely, he would have survived that demon attack. Even if he hadn't come out unscathed, he never would've allowed himself to fall like that. His pride and honor wouldn't have allowed it. Most likely, he would've continued leading his clan's armies while raising his eldest son to carry on the family legacy. Eventually, he would have retired from battle once his body could no longer bear the weight of armor, and died holding on to the blissful illusion that he had fulfilled his dream of becoming the strongest samurai in Japan.

As they say, ignorance can be both a blessing and a curse. If only Michikatsu had never crossed paths with Yoriichi again that day…

A sharp, echoing sound tore through the forest. When he opened his eyes, the calm of the snowy woods was gone, replaced by the traditional halls of the Infinity Castle, where the Upper Moons gathered.

He wondered what might have happened this time, since it was rare to be summoned in the middle of a mission.

Kokushibo's intrigue deepened when he saw the massive bloodstain in the center of the room, next to the dismembered body of the Upper Rank Two. His organs were scattered across the floor, and his head sat in one corner, grinning with disturbingly cheerful delight, as if he'd been having fun instead of being tortured.

Without a doubt, in the opinion of the Upper Rank One, it was a grotesque sight, just like Douma's sociopathic nature.

"Oh! Kokushibo-dono!" Douma greeted with his usual cheerful, mocking tone. "What a joy this is! It's been decades since you last graced me with your presence!"

The demon ignored his nonsense and turned to the second presence in the room. "Nakime. Explain what's happening."

The woman said nothing. Instead, she began plucking her biwa in various tones and melodies, opening several doors through which numerous humanoid figures emerged at high speed.

One by one, the figures approached the center, each bearing the same kanji in their eyes but with different numbers.

For the first time in 113 years, the Upper Moons had been summoned to a meeting. The last time had been due to the death of an Upper Rank demon. However, with all six crescents now present, Kokushibo had no idea what could have caused such a gathering.

"Perhaps Muzan-sama has finally found the flower," the Upper Rank One speculated.

"Well, well, well," chuckled the demon with the kanji for five, placed in the eye inside his mouth. "This is unexpected, indeed. Seeing all of us here, alive and in good health. It makes my heart beat with such joy, I feel like singing and dancing!"

"B-but Gyokko-san, if we've all been summoned, it must mean something terrible has happened!" whimpered a trembling, frail old figure bearing the kanji for four. "Terrible, terrible! What if Muzan-sama plans to punish us for still not finding the Blue Spider Lily?!"

"Shut up, Hantengu!" barked an irritated woman with the number six in her eye, causing the elder to shriek and whimper further. "We've all done our duties. If anyone here looks guilty, it's Douma-sama."

All the demons, except the Upper Rank One, turned to face the likely source of the commotion, seeking answers. But Douma only smiled brightly while he casually reattached his severed limbs, as if oblivious to any possible wrongdoing.

"Ah, Daki-chan, I doubt all this celebration is about me. I was simply at my temple, helping the poor, unfortunate souls who seek my guidance, when Muzan-sama"

"You call that fun?" asked the demon with the number three, his voice laced with disinterest.

"Akaza-dono, are you worried about me?" Douma replied joyfully, irritating Akaza further. "Don't worry, Muzan-sama enjoys very… intense games, and I am happy to offer myself for his pleasure as often as needed!"

"Disgusting," muttered the skeletal figure who also bore the number six, before being smacked on the head by Daki.

"Behave, Gyutaro. If Muzan-sama summoned us, it must be for something important."

"Of course it's important!"

Everyone flinched slightly at the overwhelming pressure in the air as Muzan descended from above, landing gracefully yet with a face twisted in fury, frustration, and what almost looked like fear.

No one wanted to be the cause of this meeting.

"Kokushibo! Did you investigate that peasant house?"

"There were no signs of survivors at the site. However, it's evident that the Demon Slayers had been there recently. Wisteria decorations covered the area, the bodies had been buried, and the house was cleaned and restored."

To everyone's surprise, the demon king's posture visibly tensed for a moment. His hands clenched tightly, veins bulging with restrained rage"Were you able to find the ones responsible?"

"I'm afraid not. The blizzard's winds covered all tracks, and the scent was completely scattered. Also, of the five bodies, only four were buried. I suspect one may have survived, though I doubt they could be of use to Ubuyashiki. The injuries would be far too severe for them to even walk—assuming they still have legs."

Muzan remained silent for a moment, pacing slowly before the Upper Moons. The tension from his earlier outburst still lingered, but the demons' unease grew even more the moment they felt his murderous aura rise once again.

"You said 5 graves?"

The demon nodded in response"Yes I do"

Muzan's expression darkened slightly, and the oppressive aura around him surged dramatically, making the Upper Moons shift uncomfortably"You didn't find anyone else along the way?"

"The place was deserted as if no one had ever lived there."

In an instant, Muzan was once again tearing apart Upper Rank Two's body, ripping through flesh and organs in a violent frenzy. The others stood in varying states of shock, fear, and disgust, except for Douma, who only smiled as if it were a delightful game with his master.

"How horrible! Please, Muzan-sama, have mercy on us!" Hantengu cried, dropping to his knees and making himself as small as possible.

"Don't say that!" Gyokko countered with fascination. "It's splendid to witness Muzan-sama's artistry with our very own eyes...or eye, in biwa woman's case."

"They're too damn loud," Gyutaro muttered irritably, only to be struck again by Daki.

"Kokushibo, explain what's happening," Akaza demanded impatiently, only to be completely ignored.

"You saw him. You saw him years ago… AND SAID NOTHING!!"

"What are you talking about?" Kokushibo asked.

"I'M TALKING ABOUT YORIICHI!!"

The room fell silent. Every demon present wracked their memories to recall if they had ever heard that name—or something close to it—but found nothing. None of them knew who this Yoriichi was, or why Muzan-sama seemed so shaken.

None of them, except one.

Kokushibo wasted no time. He ripped Douma's head from his body, plunging his claws deep into his skull and piercing through the demon's brain. Douma, ever unfazed, quickly turned his head and part of Kokushibo's hand to ice, detonating it in a small explosion of frozen shards that embedded themselves in the First Upper Moon's body.

But Kokushibo didn't flinch at the attack or the injuries. Not when his focus was locked on the flood of memories he had extracted from Douma's mind. One by one, he sifted through them, witnessing unspeakable acts of cruelty and violence, searching for any trace of what Muzan was referring to.

And then he found it…

"You are the third strongest demon. Only Muzan Kibutsuji and the First Upper Moon outrank you."

"A demon is nothing but an existence of sadness and hatred. They live only to spread death and pain…"

"…What do you take life for, exactly?"

"Even without emotion, why do you choose pain as a way to feel? Why is suffering entertaining to you? What's so amusing about this?"

"What does life mean to you?"

"Hinokami Kagura!!"

Those eyes. That crimson hair. That calm, gentle, yet intimidating gaze. The fluid stance. The serenity in how he handled the katana. But most of all—that voice, and the way he spoke.

The eldest son in that photograph was the same boy who had fought Douma. The same one with a Breathing Style similar to the Sun—more so than even the Moon Breathing itself.

The same one who had surely lived in that house… the one the Demon Slayers had visited.

A scream of pure panic from Hantengu rang out as an overwhelming aura surged from Kokushibo's body. Daki quickly hid behind her brother, who was visibly uncomfortable. Gyokko slipped into his vase to avoid attention. Akaza, meanwhile, observed with a mix of curiosity and amusement as the unshakable First Upper Moon slowly twisted into a scowl of absolute hatred and contempt.

"It can't be…"

"Muzan-sama, there's no need to worry about that child," Douma said casually. "He just caught me off guard with his innocent appearance. I'm sure—"

Any justification was silenced as Muzan crushed Douma's head in one swift motion, overwhelmed by his own uncontrollable fury and frustration. Despite how desperately he wanted to kill him slowly and painfully, he couldn't afford to lose one of his strongest demons so foolishly.

Not when a remnant of Yoriichi Tsugikuni had resurfaced,centuries later among the ranks of the Demon Slayers.

A fleshy tendril shot from Muzan's arm and pierced the remains of Douma's body, repairing every inch of damaged tissue until he was completely regenerated. To Muzan's dismay, the demon didn't seem at all shaken by his brush with death—still smiling as cheerfully as ever.

"From this moment on, all of you have one mission. Find the boy with the Hanafuda earrings and kill him as quickly as possible. I don't care if it takes all the Upper Ranks. That child must die immediately. If you fail… you won't live to try again. Understood?"

The lower-ranked demons nodded rapidly, terrified by the tension and command. Each of them committed the image of the boy to memory, now designated a priority target.

Akaza felt a rush of excitement. It was the first time the Upper Moons had been ordered to hunt a specific human. He hoped the boy was powerful, if he had stood against Douma, even briefly, it might make for a worthy battle. Still, the fact that the target was just a child made him wonder whether the kid had been lucky… or if Douma was just an idiot.

Douma, ever smiling, merely nodded in sinister delight. It had taken him days and dozens of beautiful women to fully recover from that painful encounter. Now he had the perfect chance for revenge for being robbed of the pleasure of devouring the lovely Hashira he had left half-dead.

By the time anyone noticed, Muzan had already vanished, leaving behind a thick, oppressive silence. Daki and Hantengu tried to sneak away, but in the blink of an eye, their heads were separated from their bodies.

Before them stood the imposing figure of Kokushibo, blade drawn, pure hatred burning in all six of his eyes.

"Br-brother…" Daki whimpered, barely able to speak through her terror.

Hantengu was trembling violently, nearly decapitated by fear alone. More than anything, he wanted to disappear from existence.

Gyutaro just watched the scene unfold with lazy detachment. Maybe his sister would finally learn to think before acting. Yes, that was why he wasn't doing anything. Not because he was utterly paralyzed by the overwhelming pressure of Kokushibo's power.

Akaza simply frowned at the drama, while Douma readied his fans in case the First Upper Moon decided to "invite" him to play. If that happened, he would gladly accept a duel with the great swordsman of the Sengoku era.

"Kokushibo-dono," Gyokko spoke respectfully, his head poking slightly out from within his vase. "Pardon the interruption, but could you tell us why you attacked our comrades so suddenly?"

"In light of recent events, and considering the urgency of Muzan-sama's new mission, I am imposing an additional order. Whoever encounters the boy must report to me immediately, so that I may be the one to kill him with my own hands."

Akaza's irritation turned to anger at the thought of giving up the thrill of combat to Kokushibo.

"And why should we do that?"

At those words, Kokushibo's katana shot toward Akaza with intent to slice him in half. Akaza was already preparing to deflect the attack and counter with his most powerful technique, when a frozen figure suddenly appeared between them, blocking the blade but shattering in the process.

"Dhostha, Dhostha!!" Douma shouted gleefully as he stepped between the two demons. "There's no need to get defensive. We're all friends here, right Gyokko-san?"

"I wouldn't quite call us friends," the aforementioned demon murmured thoughtfully, twisting through the air now that the tension had lessened. "But we should at least act in harmony if we want to preserve the balance and perfection among the Upper Ranks."

"Exactly! Don't worry, Kokushibo-dono. If any of us find the boy, we'll let you know so you can finish him however you wish, right everyone?"

All of them nodded in agreement.

"It's good to see such a collaborative spirit. This mission's importance could rival even the search for the Blue Spider Lily, so I trust you'll all follow the First Upper Moon's directive to fulfill Muzan-sama's wishes."exclaimed Nakime

With the meeting concluded, the familiar sound of the biwa echoed once again, and all the demons returned to their respective domains, now with new orders to fulfill.

Kokushibo glanced around at the metallic structures scattered throughout the chamber, blocks of iron, diamond, and other incredibly hard minerals, all placed there to help him refine his technique and perfect his combat style.

The news had initially blinded him with rage, but after thinking it through with a clearer mind, he saw the unique opportunity fate had presented him. His greatest frustration in life had always been that no matter how much he trained or improved, he would never know if he could surpass his brother's divine talent, since Yoriichi had died long ago. He had lost his final chance when they crossed paths during Yoriichi's old age. And even in old age, Yoriichi had shown overwhelming power and skill, far beyond Kokushibo's own.

He still remembered his brother's final words and the profound disappointment in his tone.

"…This is heartbreaking."

But now, it seemed he had another chance.

All the fury he'd kept buried surged out at last, taking the form of lunar slashes and thrusts, tearing through the room in all directions until nothing remained but dust.

Perhaps Yoriichi himself hadn't returned and never would. But an echo of his being had reappeared after all this time. And Kokushibo would train to his utmost, for he intended to prove that the shadow of the moon could one day eclipse the blinding light of the sun.

A/N: Well well, I think nobody expected a chapter dedicated exclusively to the Upper Moon and the demons, but I think that in every story, the antagonists should have the same development as the protagonists. The encounters will be more exciting and you can better understand the motivations that led them to go against what they swore to protect. (Ahem for those who follow my Crossover story with BNH, if you liked this type of development, I can say that the one you will have the antagonists of that story will be much better than in this one lol)

Also, this is not only Tanjirou's story, but also Yoriichi's and therefore Michikatsu's and what happened before becoming Kokushibo.

Mind you, I'm not going to say that everything is Yoriichi's fault or make Kokushibo a victim of Yoriichi's accidental indifference, but I also like to see and analyze those events from Michikatsu's perspective. In the story it was clear that he genuinely loved and cared for his younger brother and it wasn't when he saw that he was a prodigy that he felt envy and jealousy, but I think that if Yoriichi had been more expressive with his words and actions, perhaps Michikatsu would have had more doubts about his decision to betray the Demon Slayers, I would like to explain my point more but that would be giving Spoilers so we will have to wait for the next chapters.

Even so, now the demons know of the existence of Tanjirou Kamado and he is now a target for the Upper Moon, this will undoubtedly bring many complications for our beloved swordsman. Who do you think will be the first to find him? Maybe Akaza and they will have a solar duel against the solar swordsman? Or maybe Gyutaro and Daki will find him unexpectedly outside the red light district? It could be that even Kokushibo will find him on a mission and see firsthand that maybe there is more than just a remnant of Yoriichi in Tanjirou. But that's for future reference.

If you liked it, don't forget to leave a comment to share your opinion, theory, or even an idea that could be used in the future (obviously giving credit for the idea).

Thanks for reading :)