Every movement had to be precise.
Every breath, deliberate.
Every mistake, costly.
I learned that lesson the hard way.
At five years old, I woke up before the sun. Not because I had to—but because I couldn't rest knowing how far I still had to go. The cold bit into my skin as I stepped barefoot outside the house, snow crunching softly beneath me. My breath fogged the morning air, the same way Father's did when he danced the Hinokami Kagura—the Dance of the Fire God.
I mimicked the first form. Slowly.
Flame Dance.
Right foot forward. Pivot. Sweep. Inhale. Exhale. Rise.
I slipped and fell face-first into the snow.
Again.
I stood, ignoring the stinging pain in my wrist. The bruises didn't matter. What mattered was control—learning to blend form and breath as if they were one. I didn't have access to real Breathing Techniques yet, not the way the Demon Slayers would. I lacked the experience, the battle instincts, and the Nichirin Blade. But what I did have was time, and a slow-burning fire that refused to be extinguished.
---
Father watched me silently one morning.
He didn't say anything for a while, just stood there with his thin shawl, looking more frail than ever. His illness had worsened over the past year. Each winter took more from him. But he never once failed to perform the dance on New Year's Eve, every movement filled with grace and quiet strength.
"You dance with too much tension, Satoshi," he said finally, his voice like cracked parchment. "Your steps are filled with fire, but your soul feels heavy."
I wanted to tell him why.
I wanted to say that his death was written into a story I used to watch for fun. That he wouldn't live to see Tanjiro's growth, Nezuko's transformation, or the day Muzan spilled our family's blood.
But I just nodded. "I'll improve, Father."
He smiled, that tired, proud smile of his. "You already have."
That night, he danced again—his back straight, his eyes half-closed, breathing in rhythm with the firelight. I watched with awe. This wasn't just a tradition. This was power hidden beneath ritual. It was the origin of every breath style. And I had to master it.
---
The days turned into weeks, and weeks into years.
By the time I turned six, my body had hardened. The constant repetition of the dance, the early-morning runs through the woods, and my obsessive focus on detail forged something new inside me. I hadn't yet awakened true Breath of the Sun, but I was close.
I felt it when my lungs adjusted, expanding and contracting with purpose.
I felt it when the frost no longer numbed my bare feet during morning training.
And I felt it when the villagers started calling me "the Flame Child" behind affectionate smiles.
"Your boy," I overheard once, "he doesn't act like other children."
My mother always laughed, brushing it off. But she was worried. I could see it in her eyes. She thought I was overworking myself. Perhaps I was. But she didn't know what I knew.
---
Tanjiro was growing fast.
He was a gentle, curious boy—always asking questions, always helping around the house. He didn't have the burden I carried, and I prayed he never would.
One evening, I watched him feed the fire, his face glowing orange in the hearthlight.
"I want to be strong like you, Nii-san," he said.
I froze.
You are, I wanted to say. Stronger than you know. But strength will bring pain too.
"Then stay kind," I replied softly. "Kindness is strength."
He didn't understand yet. But one day he would.
---
At seven, I began experimenting.
If I was going to have any chance at protecting my family, I couldn't rely on dance alone. I needed to understand how Sun Breathing worked as a combat art. That meant testing each form's application—not just for performance, but for offense, defense, and evasion.
I built a crude dummy from logs and straw. I used sticks and old tools as makeshift weapons. I studied how the breath flowed through the body with each movement.
And slowly, I learned.
Second Form: Clear Blue Sky – A spinning, circular slash. Too wide. Leaves you open.
Third Form: Raging Sun – Twin strikes. Powerful but easy to read.
I kept notes on everything—carved into bark, written with charcoal, etched into memory.
I wasn't just practicing. I was preparing for war.
---
Then came the first turning point.
A bear.
It came down from the mountain during an early spring melt—massive, ragged, and angry. I had been out gathering firewood alone. It saw me before I saw it. There was no time to run.
My body moved on its own.
Flame Dance.
Inhale. Shift. Step. Strike.
My wooden stick met the bear's face—not enough to kill, but enough to redirect. I jumped to the side, exhaling sharply, knees bent. The adrenaline sharpened my senses. My breath came in waves—controlled, rhythmic.
The bear roared and fled.
I stood frozen, heart pounding, stick cracked in half.
That was real.
I collapsed to my knees, not from exhaustion—but from the overwhelming realization:
The Dance of the Fire God could work.
---
From that day, I doubled down. My training grew more intense. I added strength exercises—stone lifting, tree climbing, controlled breathing under a freezing waterfall.
Every blister, every cut, every bruised rib brought me closer.
I wasn't Yoriichi. I never would be.
But I didn't need to become the strongest Demon Slayer in history.
I just needed to become strong enough.
Strong enough to stand between Muzan and my family.
Even if it killed me.