"A sword is fragile," said Sakonji Urokodaki, his voice steady behind the tengu mask. "It can endure great longitudinal force, but almost no lateral strain. When you swing, your blade and motion must stay perfectly aligned. Even a slight deviation weakens the strike—or shatters the weapon outright."
As he spoke, he raised his own blade and demonstrated. With one smooth motion—shff!—the sword cut cleanly through a thick wooden post.
Don't underestimate that feat. Splitting a log like that wasn't just about strength—it was control, precision, and unity of breath.
Tanjiro Kamado, wide-eyed with admiration, immediately took his turn. He roared, swung hard—
Thud.
The sword stuck halfway through the wood.
Despite his raw power, his angle was off. Fear of breaking the weapon held him back.
Urokodaki sighed. He wasn't surprised—but a lecture was still in order.
While he corrected Tanjiro's posture, Chika Kamado quietly gripped the sword Urokodaki had handed her. Her eyes drifted to the post Tanjiro had failed to cut.
Then—whsh!
The blade flashed. The post split neatly in two, one half rolling slowly to the floor.
Both Tanjiro and Urokodaki froze, necks creaking as they turned toward her.
"S-Sister… how did you…?" Tanjiro stammered.
"Uh… I just… did it?"
Chika blinked, almost embarrassed. The truth was, the moment she touched the sword, she'd felt something—an instinctive flow. She'd simply followed it.
Then realization dawned, and she declared with utter seriousness,"Well, a kitchen knife is still a knife, right? I've been using one my whole life!"
Chika's First Theory:A knife is still a blade!
Urokodaki nearly face-faulted behind the mask. Technically true—but hardly logical. A cook's knife and a katana weren't interchangeable.
Still, Tanjiro's eyes lit up in sudden clarity."Oh! That makes sense! Sister, you've always been amazing with a knife!"
He wasn't wrong.Back home, their father's poor health meant the older children took over housework early.Nezuko handled sewing and the younger siblings.Tanjiro chopped wood and managed errands.Chika ruled the kitchen.
Her knife work had been a family legend—swift, precise, graceful. Tanjiro had often stood in awe at the rhythmic sound of her chopping, the blur of motion that looked almost… artistic.
So when he saw her cut a log in one stroke, he wasn't even shocked anymore.If anyone could bridge cooking and swordsmanship, it was his sister.
Grinning, Tanjiro tightened his grip on his sword. If Sister can do it, I'll master it too.
In the original timeline, Tanjiro trained for two full years under Urokodaki before mastering all ten forms.But with Chika here, his motivation had doubled.
He wasn't alone anymore.
While Nezuko slept peacefully in her box, Tanjiro threw himself into training, and Chika began exploring the mysteries of her own body.
Though she no longer needed the wheelchair, her stamina still lagged. She tired easily, even when her strength felt… unnatural. A strange balance—like her body demanded an "equal exchange" for its power.
She trained in Water Breathing alongside her brother. Some might ask—why not the Hinokami Kagura, the Fire God's Dance?
Simple: it was too much.
The Hinokami Kagura—the ancestral Sun Breathing—was overwhelming. Even Tanjiro, two years later, had nearly collapsed after just a few swings of the flaming dance. It was like trying to cast a high-level spell with no mana left—you could, but you'd bleed yourself dry.
Water Breathing, on the other hand, was gentler—one of the five foundational Breathing Styles. Balanced, fluid, adaptable. Most Demon Slayers began with it.
Its ten forms were both beautiful and deadly:
First Form: Water Surface Slash
Second Form: Water Wheel
Third Form: Flowing Dance
Fourth Form: Striking Tide
Fifth Form: Blessed Rain After the Drought
Sixth Form: Whirlpool
Seventh Form: Drop Ripple Thrust
Eighth Form: Waterfall Basin
Ninth Form: Splashing Water Flow – Turbulent
Tenth Form: Constant Flux
Each carried its own rhythm and mood: the graceful dance of Form Three, the mercy of Form Five, the relentless tide of Form Ten.
Chika practiced diligently—and one day, when her blade traced the arc of a Water Surface Slash, blue ripples shimmered outward like liquid light.
Her breath hitched.Was that… actual water?
A closer look revealed the truth—it wasn't real water, but sword-aura, the visualization of her breathing's flow.
Of course, she thought. If Water Breathing truly released water, Fire Breathing would ignite flames, and Thunder Breathing would strike lightning.
If that were literal, the Demon Slayer Corps wouldn't just be warriors—they'd be walking natural disasters.
Days turned to weeks.Both siblings improved far faster than Urokodaki had ever expected. His training schedule, carefully crafted over years, fell apart under the speed of their progress.
Night descended.
Chika lay on her futon, staring at the ceiling. Slowly, her eyes closed.And once again, the same dream returned—the one that had haunted her since she arrived in this world.
The Kamado home, warm and peaceful.Their mother—gentle, kind.Nezuko, graceful and sweet.The younger siblings, playful but well-behaved.
Chika stood in the kitchen, inspecting the ingredients on the counter, wondering how to make the night's meal even tastier.
Then—
Knock. Knock. Knock.
"Who's there?" she called.
"It's not Brother—he just left," one of the children answered.
"I'll get it! I'll get it!" cried Takeo, racing to the door.
"Slow down, Takeo," their mother called, rising to follow.
Click.
The door slid open.A man in a black suit stood outside—tall, pale, smiling faintly. His features carried an uncanny resemblance to Michael Jackson.
"Good evening," he said pleasantly.