The Kocho sisters' morning meals at the Akatsuki Trading Company mansion were peculiar, but simultaneously warm.
The meal brought by the oni attendant Ubume was an unsurpassable feast for the human girls, and the gazes of Akira and the heroic spirits watching them held a strange sense of expectation.
When the meal ended and digestion was due, Akira took the sisters to the mansion's underground training hall. Two wooden swords were already prepared there.
"Now, listen up."
At Akira's words, Kanae and Shinobu picked up the wooden swords. Perhaps due to their still-lacking muscle strength, Shinobu's arm wavered under the weight of the heavy oak wooden sword.
"Heavy? That's the weight of the responsibility you must shoulder, and the weight of survival. A part of it."
Akira walked slowly with his hands behind his back and began speaking. The education about to begin wasn't merely about training the body. It was time to instill the knowledge and philosophy to fight against the calamity called oni.
"The reason I'm teaching you swordsmanship is simple. Because it's the most efficient means to kill oni."
"But... you said oni don't die even if beheaded, Akira-san. Not without sunlight, or special power."
Kanae asked carefully.
"Correct. So for hundreds of years, humans created an organization called the Demon Slayer Corps to oppose oni. They use blades called Nichirin Blades made from ore imbued with the sun's energy, and a technique called Total Concentration Breathing that dramatically enhances physical abilities."
"Total... Concentration Breathing?"
Shinobu's eyes sparkled.
"Yes. A technique that fills the lungs with oxygen to accelerate blood circulation and heart rate, raising body temperature and muscle strength to unleash power capable of fighting oni equally. Water, Flame, Wind, Stone, Thunder. There are basically five main Breathing styles, with numerous derived Breathings existing from them."
Akira paused briefly, then added with a bitter expression.
"But unfortunately, none among us can use Breathing. I can't teach you Breathing immediately. But you don't need to be disappointed. Looking at the Demon Slayer Corps' history, even before Breathing was systematized, excellent swordsmen slew oni with swordsmanship alone."
"Then... can't we join that Demon Slayer Corps place and learn?"
Shinobu asked innocently. It came from the thought that if it was an organization that killed oni, wouldn't it be the most ideal place for girls dreaming of revenge?
But as soon as those words fell, Akira's expression froze coldly.
"Never, do not associate with those bastards."
The disgust in his voice wasn't merely emotion directed at an敌对势力. It was contempt.
"Their will to fight oni is genuine. But their methods... are rotten enough to make you nauseous."
"Rotten... you say?"
In response to Kanae's question, Akira gave an example.
"A representative example is the entrance exam called the Final Selection. They force children who come to become Demon Slayers to survive for a week locked in mountains swarming with oni."
The sisters' eyes widened.
"No support, no supervisors. Just give them one sword and drive them to their deaths. It's a group where dozens enter and even if only three or four survive, they dismiss it as 'a good harvest this time.' Dead children? They're just left as having died from lack of skill. They don't even recover the bodies. No, the dead become a meal for oni in the first place."
Akira clenched his fist tightly.
"Treating young children who come burning with revenge or with a sense of justice as expendables like that—that's the Demon Slayer Corps. They claim to hunt oni to protect humans, but they don't know how to protect their own members. They're fools who've maintained that kind of operation for hundreds of years under the guise of tradition."
"Th-that can't be..."
Kanae covered her mouth. The reality of the Demon Slayer Corps, which she had thought were righteous apostles hunting oni, was too shocking.
"So you will grow strong not by the Demon Slayer Corps' way, but by my way. I won't drive you to your deaths. I'll prepare you perfectly, make you the strongest, and ensure you return alive. Understand?"
"Yes...! We understand!"
The sisters bowed simultaneously. Their幻想 of the Demon Slayer Corps was shattered, but instead, their trust in Akira grew even firmer.
"Now now~ That's enough serious talk! Shall we loosen up our bodies a bit?"
Descending to the training hall with cheerful voices were Okita Souji and Ushiwakamaru. The two were among Japan's historically greatest swordsmanship geniuses.
"Starting today, I'm Okita Souji in charge of your swordsmanship guidance! This is Ushiwakamaru-san."
"Nice to meet you! By my lord's command, I'll make you into warriors who can take on a hundred alone!"
Ushiwakamaru swung a wooden sword with a spirited smile. A WHOOSH~ sound tore through the air. Shinobu made a frightened expression at the sound.
"Um... we've never even held a sword before..."
"Don't worry! Everyone's like that at first. I also started by learning how to hold a bokken. Though I did beat up my teacher on the first day."
Okita said something terrifying with a bright smile. The standards of geniuses differed from ordinary people, but fortunately, they were quite thoughtful in their teaching methods.
"Now, Shinobu-san. Relax your shoulders. You don't swing the sword with just your arms, but with your waist and lower body."
Okita approached behind Shinobu and corrected her posture.
"Your sword tip is shaking. Don't grip too tightly, hold it softly like holding an egg. But firmly at the moment of cutting!"
"Ugh... It's too hard..."
"Kanae, you're taller than Shinobu, so use that distance. Don't just think about defense, remember that attack is the best defense! Anyway, once you learn our footwork techniques, even Lower Moons won't be able to touch you!"
Ushiwakamaru watched Kanae's posture and explained the footwork she learned from the tengu Kiichi Hogen at a very basic level.
"First is basic stamina. No dinner until you swing the wooden sword a thousand times!"
"Whaaat?!"
Shinobu screamed, but the two genius teachers had no intention of going easy. But it was different from the Demon Slayer Corps' neglect. When posture collapsed, they corrected it; when breath reached the tip of their chins, they taught breathing techniques and adjusted the pace.
It wasn't abuse or neglect, but true education.
As the sun began to set, the sisters who finished training lay sprawled on the floor, drenched in sweat. Blisters had formed and burst on their palms, and their limbs trembled. Barely over a hundred total swings, let alone a thousand.
Kanae was 13, Shinobu barely 10 years old.
But by the standards of heroic spirits who lived through eras of war and slaughter, it was a sufficient age. Even Kiyohime at 12 had already mastered wielding a naginata at a high level as part of noble upbringing since she was younger.
King Arthur began receiving swordsmanship, kingly studies, and various trainings from Merlin at just 5 years old, and Yorichii, this world's strongest swordsman, at less than 10 years old on the day he first held a sword, shattered the bones of and knocked out a skilled swordsman hired by the Tsugikuni family, who was excellent even by Sengoku period standards.
Unfortunately, even if they said they were teaching by ordinary people's standards. The standards of heroes who experienced all battles were too high, so what they thought were ordinary people's standards were also endlessly high.
"Now... I can't move anymore..."
Shinobu mumbled with a tearful face. Then, a delicious smell struck her nose.
"You've worked hard, both of you! Now, it's nutrition replenishment time!"
Tamamo-no-Mae and Kiyohime appeared carrying huge trays. On the trays were mountainous piles of high-rice bowls, pork stew full of meat, and various nutritional foods.
"Are... we supposed to eat all this?"
"Of course. To become warriors, stamina is fundamental! You need to eat a lot for muscles to build and height to grow."
Tamamo smiled slyly and placed a rice bowl before Shinobu.
"Those Demon Slayer Corps bastards would just throw rice balls at you, but our Akatsuki Trading Company is different. It's a perfectly calculated diet with the protein and calcium needed for growing adolescents! Leaving food means penalty points!"
Kiyohime said while placing a plate full of stir-fried pork and vegetables.
"Uuu..."
Shinobu and Kanae picked up their spoons with tearful determination. But the moment they took a bite, their eyes widened.
"It's delicious...!"
Tamamo and Kiyohime's cooking skills were at a level rivaling first-class chefs. They could feel energy flowing into their tired bodies. Akira watched the scene contentedly from a distance.
'Yes, eat. Eat a lot and grow. Grow up strong and healthy.'
In the sisters moving their chopsticks, he saw the wingbeats of butterflies that would someday bloom. Though they had no Breathing, if raised under this systematic and abundant support, they would become much stronger and sturdier swordsmen than in the original story.
"Akira-san, eat with us too!"
Kanae called Akira with rice grains sticking to the corner of her mouth. Akira shook his head with a bitter smile.
"I'll eat separately later, so you two eat a lot together."
Seeing his bitter smile, Kanae didn't insist further. She had spoken from a pure heart in a moment of happiness, but knowing what he had to eat. Instead, she vowed in her heart.
To someday create a world where that person wouldn't have to eat so lonely.
The Akatsuki Trading Company's training hall was filled with the heat of training and warm food smells. This was a new form of nurturing possible only here, absent from the Demon Slayer Corps' history.
"Nobbu. You catch a swordsman who uses Flower Breathing or maybe Water Breathing."
"Me?"
"You can fly in the sky. With Tamamo's talismans, no one will see you, so travel around as much as possible."
"Sigh, what a bother."
And Akira tells Nobunaga to capture a swordsman who uses Breathing. The Breathing the sisters use is Flower Breathing. Shinobu's Insect Breathing is derived from that Flower Breathing. And Flower Breathing itself is derived from Water Breathing.
Basically Flower Breathing, but at minimum bring a Water Breathing swordsman to teach Breathing. Even an unskilled one will do. What's important is the Breathing itself, not the form.
There's no right of refusal. We can manipulate their mind through suggestion, and one swordsman going missing is nothing. If we remove the crows and there are no witnesses, they'll just assume they were killed by an oni. Anyway, it's an organization where ordinary members are nothing but disposable pawns.