Do you have a Power Stone? Give it to me.
---
The Taisho Era was, for this island nation, a rare period of relative peace.
"Huff... huff..."
Late night on the streets of Tokyo, the dim yellow of streetlights mixed with the dazzling colors of neon signs, barely illuminating the darkness of this city.
A man dressed in a black tailcoat was desperately sprinting down the deserted street.
"Save me... my lord... save me..."
Rapidly passing through one street after another, the man seemed to have a clear destination. While continuously running in a fixed direction, he constantly looked back at the seemingly empty darkness behind him.
The man had deathly pale skin, a slender build, light blue pupils, and black medium-length hair.
On each side of his cheeks were three strange square marks, appearing quite bizarre—not like a normal human.
In fact, this was indeed the case. The man was not human. The characters "Lower Rank Two" engraved in his pupils had already revealed his identity—
Of the demon clan, the current Lower Rank Two of the Twelve Kizuki: Enmu.
At this moment, he was fleeing from Demon Slayer pursuit.
Several hundred meters behind Enmu, two figures were rapidly shuttling between tall buildings, closely chasing his position.
These two figures were one male and one female.
Among them, the male had long black hair tied in a small braid, with dead fish eyes, forever maintaining that expressionless dead look no matter who he faced.
This person was none other than one of the current three Water Hashira of the Demon Slayer Corps—Tomioka Giyuu.
Giyuu, apprenticed under former Water Hashira Urokodaki Sakonji of the Demon Slayer Corps, had his family pass away one after another when he was very young, leaving only an elder sister to depend on with him.
However, good times did not last. Several years later, his only sister was killed by a demon at her wedding. Only the young Giyuu survived because he hid in a cabinet.
After this, the devastated Giyuu happened to encounter Urokodaki Sakonji and was taken in as his disciple, beginning to learn Breathing Techniques from then on.
Several years ago, he participated in the Demon Slayer Corps' Final Selection together with his senior disciple Sabito and junior disciple Makomo, who were also disciples of Urokodaki Sakonji, and successfully passed the selection, becoming a formal Demon Slayer.
Now several years had passed, and these three had successively been promoted to Water Hashira of the Demon Slayer Corps.
And the female beside Giyuu was undoubtedly the current Flower Hashira of the Demon Slayer Corps—Kocho Kanae.
Kanae had smooth, long black hair, with butterfly hair ornaments on each side. She had purple pupils and always wore a smile on her face. She was the gentlest woman in the current Demon Slayer Corps.
Kanae's reason for joining the Demon Slayer Corps was different from Giyuu's. She held no hatred toward demons.
Due to some rather complicated reasons, Kanae had left home with her mother when she was extremely young, breaking away from her original family.
Ten years ago, Kanae's mother happened to encounter a Demon Slayer.
Due to her outstanding medical skills, Kanae's mother accepted the other's invitation, not only joining the Demon Slayer Corps and becoming a physician there, but also establishing the most important medical institution within the Demon Slayer Corps—the Butterfly Mansion.
That year, Kanae was thirteen.
It was also from this time that she first came into contact with the existence of Breathing Techniques.
The swordsmanship talent sleeping within her gradually manifested. Kanae, who had almost self-taught mastery of Flower Breathing, successfully passed the Final Selection a year later, becoming a formal Demon Slayer from then on.
And several years after that, she smoothly rose to become the Flower Hashira of the Demon Slayer Corps, becoming the only female Hashira-level swordsman in the Demon Slayer Corps at that time.
But it was also in the same year that Kanae was promoted to Hashira that her mother passed away from illness.
It was a very sudden acute illness. Within just a few short days, her mother went through the entire process from falling sick to passing away, departing from this world.
And several years before that, when their family had just joined the Demon Slayer Corps, Kanae's grandmother who had remained at the old home had also passed away from illness...
Did the Butterfly family seem to have some hereditary family illness?
Kanae did not know.
She only knew that for now, neither she nor her sister showed any signs of illness.
That's right, Kanae actually had a younger sister four years her junior, named Kocho Shinobu.
Completely different from her elder sister Kanae, younger sister Shinobu's personality was not only far from gentle, but rather irritable, exploding at the slightest provocation.
A small stature paired with that explosive little temper—truly quite adorable...
Unlike her elder sister Kanae, Shinobu did not choose the path of the Demon Slayer.
Although she had also come into contact with Breathing Techniques when young, Shinobu did not display any exceptional talent in Breathing Technique cultivation.
Her body was incompatible with all Breathing Style schools within the current Demon Slayer Corps.
When she heard the news that her elder sister had successfully passed the Final Selection, the two paths before Shinobu at that time were:
First, to find a way to create a new Breathing Style school suitable for herself, then follow in her elder sister's footsteps and similarly walk the path of the Demon Slayer.
Second, to completely abandon the path of the Demon Slayer and instead focus entirely on studying medicine, becoming a logistics medical personnel of the Demon Slayer Corps from then on.
According to normal story development, fate might have wanted Shinobu to choose the first path and become a Demon Slayer like her elder sister.
But ultimately, Shinobu still chose the second path through her own will.
Frontline combat had her elder sister—that was enough. Anyway, she herself didn't have much talent for Breathing Techniques.
Since that was the case, she might as well directly give up and instead exert her talent in medicine, where she was more skilled.
This way, perhaps she could provide more help to everyone...
The later story development proved this was indeed the correct choice.
To this day, Shinobu was not only the most outstanding physician within the Butterfly Mansion, but also personally managed all medicinal material procurement matters for the Demon Slayer Corps.
Not only that, thanks to some related papers she published in newspapers not long ago.
The eighteen-year-old Shinobu was not only invited by Tokyo University and granted the position of "Honorary Professor," occasionally needing to give lectures to students of the medical department.
She also directly skipped all related examination processes, simultaneously obtaining dual doctorate degrees in Toxicology and Pharmacology—truly boundless prospects!
Considering that Shinobu herself had no foundation in Breathing Techniques, and external exchange could also improve her medical accomplishments.
The current Master of the Demon Slayer Corps, Ubuyashiki Kagaya, specially permitted Shinobu to move freely in outside society, provided she did not reveal Demon Slayer Corps intelligence.
For the current Demon Slayer Corps, this pair of Butterfly sisters was absolutely crucial...