Three months were enough for many things to happen.
Rengoku Kyojuro had been gravely injured. Especially that final kick from Akaza—it had shattered his sternum and nearly pierced his heart.
Fortunately, Tanjiro and the others had only suffered minor injuries. They rushed Asuka and Kyojuro to a nearby infirmary at top speed, where both received emergency treatment.
Even while unconscious, Kyojuro had continued using Total Concentration Breathing to stem the bleeding from his ruptured vessels. That was the only reason he managed to hold on until help arrived.
Now, he had passed the critical stage and was slowly recovering at the Rengoku estate.
As for Asuka, his condition had been far worse.
Bones throughout his body had been shattered, and his chest had collapsed inward, terrifying even the physicians treating him.
If not for his faint but steady breathing—and the unbelievable sight of his fatal wounds slowly knitting themselves back together—everyone would have believed he truly wouldn't survive this time.
The word "miracle" had already been used far too many times for this boy.
Meanwhile, Tanjiro and the others were assigned new missions, continuing their own training and trials.
Early the next morning, Asuka was already able to sit up on his own.
Looking at Shinobu Kocho, who had brought him a basket of fruit, he spoke hoarsely, "Shouldn't you sleep a little longer? You were busy half the night."
"…You really scared everyone this time, Asuka." Shinobu gave him a mildly reproachful look as she set the basket on his bedside table. "I almost thought you…"
"And Rengoku asked me to tell you once you woke up: thank you very much for your help."
Asuka rubbed his still-aching chest and picked up an orange. "Everyone's okay, right?"
Shinobu checked his pulse and smiled helplessly. "Don't worry. Everyone's safe. You protected them."
"…I see."
Asuka nodded and said nothing more.
Seeing his quiet expression, Shinobu asked gently, "I heard the demon this time was an Upper Rank?"
"Yeah. Upper Rank Three."
"…That's terrifying. Just the third strongest and it left you and Rengoku severely wounded." She murmured to herself, a firmer light rising in her eyes. "I'll work even harder on my research. I will find a lethal poison capable of killing the Demon King Muzan."
"Poison?" Asuka turned his head curiously. "Have you always fought using poison?"
Come to think of it, aside from seeing Shinobu confront Giyu Tomioka once, Asuka had never actually seen her fight.
Shinobu drew her Nichirin Blade. The blade itself was missing entirely, leaving only a slender tip.
"My sword was specially customized by the chief of the Swordsmith Village. It's quite unique…"
She pointed to the glint at the tip. There was a small groove there.
"I inject wisteria poison into the blade. It's a toxin that restrains demons. Just fifty milligrams is enough to kill one."
When she mentioned wisteria poison, her gaze flickered slightly, as if there were more she hadn't said.
"Is it harmful to humans?" Asuka asked. "If you're not careful, could you poison yourself?"
"Ah, Asuka, you're still as blunt as ever."
She sheathed her sword with an easy smile. "Don't worry. Wisteria poison is only mildly toxic to humans. Unless you drink it like water, it won't cause any problems."
Is that so…
Asuka could sense it—whenever the topic of wisteria poison came up, Shinobu's emotions wavered in subtle ways.
He hoped she truly wouldn't be harmed because of it.
Later that day, the Master's Kasugai Crow arrived at the Butterfly Mansion.
It studied Asuka curiously, unable to hide the confusion in its gaze. "Good day, Asuka. How is your health?"
"Everything is normal."
"…You and Kyojuro are miracles of the Demon Slayer Corps. Until now, no swordsman has survived such a ferocious assault from an Upper Rank…"
The messenger fluttered its wings and hopped onto his bedside. "And… you even managed to sever the neck of an Upper Rank demon. That is truly the best news in a hundred years."
"It's a shame we couldn't kill it…" Asuka murmured.
"There is no need for self-blame. Upper Rank demons are not ordinary demons. They have wreaked havoc for centuries; they cannot be slain so easily." The messenger's reassurance eased his heart somewhat. "Additionally, the Master has special arrangements for you."
Asuka looked calmly at the crow as it continued:
"According to Kyojuro, during your battle against Upper Rank Three, you displayed strength capable of turning the tide and thus preserved everyone's lives."
"The Master decrees: although there has never been such a precedent within the Corps, the times have changed. Perhaps this is also a sign that our generation will finally bring the era of demons to an end."
"Asuka, from this day forward, you are the tenth Hashira of the Demon Slayer Corps!"
"Your title shall be—'The Storm.'"
Storm…
Asuka recalled the final moments of that battle—how, guided by pure combat instinct, he had altered the rhythm of his breathing.
"So I'm the Storm Hashira?"
"Indeed, Asuka."
The messenger bowed respectfully. "Thank you for your contributions to the Demon Slayer Corps. The Ubuyashiki family offers you its most sincere gratitude."
"As for what comes next, the Master hopes you will focus on recovering. There is no need to force yourself." It smoothed its feathers as if smiling. "Why not return to Hayama for a visit? I believe Mr. Arasaki would be pleased."
In the past, Wind Breathing had not stood among the most prominent of the five major styles. Only in this generation, under the Wind Hashira Sanemi Shinazugawa, had it risen to greater heights, elevating the overall standard of the training estate in turn.
Asuka's still-developing Storm Breathing had been born from Wind, and could be considered the pride of the entire Hayama training estate.
Though Asuka had never cared much for empty titles, the thought that becoming a Hashira meant he hadn't shamed his teacher made him nod quietly.
"Also…" The messenger glanced uncertainly at the Nichirin Blade resting beside his bed. "According to Tanjiro and the others, your blade ignited during the battle? And strange markings appeared on your body? Is that true?"
"…I'm not sure. The fight was too intense. I'm still trying to sort it out."
Asuka wasn't lying. He truly didn't know whether it had been Nugata's power again, or something he had unconsciously triggered himself.
He only vaguely remembered that his strength had surged far beyond normal, and that his blade had burned like fire.
At the same time, the burden on his body had been immense—his heart had felt as if it were on fire.
The messenger nodded. "Do not force yourself. The days ahead are long. You can recall it slowly."
"Coincidentally, I have a story to tell you."
Its voice became slow and distant, like someone recounting ancient history.
"It is said that during the Warring States period…"
At the same time, within the Ubuyashiki estate—
"Tianyin! Tianyin, do you understand what this means?!" Ubuyashiki Kagaya, no longer calm as usual, propped himself up from his bedding in agitation. "The marked swordsman who struck down an Upper Rank has awakened! He did not die. Upper Ranks are not invincible… cough, cough…"
His excitement was so intense that as he clutched his wife's hand, blood spilled from his mouth.
The Ubuyashiki illness had worsened. The scars on his face had spread to his neck, and his complexion had grown even paler.
"Kagaya… calm yourself."
"Haha… yes, I must calm down… But it has been a hundred years, Tianyin! A hundred years! We have not defeated an Upper Rank in a hundred years!"
Though he agreed in words, his emotions did not settle. Even his coughing carried laughter.
"In the Warring States era, the first generation of Hashira once drove Muzan Kibutsuji into a desperate corner!"
"It is said that markings similar to demon crests appeared on their bodies!"
"Asuka is no ordinary child! He severed the head of Upper Rank Three. He awakened the mark…"
"Although centuries have passed and we no longer know the conditions for awakening the mark, the words passed down through generations cannot be wrong—once one person awakens it, more swordsmen will be influenced by him and resonate, awakening one after another!"
"Do you understand? The era is about to change!"
"Muzan Kibutsuji will die in our generation!"