After Father and Mother's quarrel, brother Yoriichi was allowed more time outside, sometimes even attending lessons with Elder brother Michikatsu.
A year passed like this.
Father transferred the position of heir from Elder Brother Michikatsu to Brother Yoriichi, solely because, at such a young age, Yoriichi's skill with the sword already rivaled that of grown men.
Brother Yoriichi moved out of the cramped attic, donned fine clothes, and Father laughed loudly, praising him as a son to be proud of.
But Brother Yoriichi was unhappy.
Brother Michikatsu was unhappy too.
Mother was also unhappy—she quarreled with Father once more.
The only one who remained happy was Father.
On the third day after Father announced the change of heir, Brother Yoriichi left me a letter and disappeared from home.
The letter read: [Hiru, I'm sorry. Please think of me as dead.]
Father flew into a rage, cursing Brother Yoriichi as unfilial, selfish, and uncaring toward the family.
Brother Michikatsu regained the position of heir. He still looked after me, but he never smiled again.
Half a year later, Mother passed away.
Brother Michikatsu wept bitterly, but I saw a shadow in her likeness. She gazed at him with sorrow, as if trying to embrace him. The shadow lingered for a long time before finally fading away.
Gradually, I came to understand—the shadow was the human soul. When it appeared, the soul would weaken under its pull. When the shadow grew clear, the soul would leave the body. And without a soul, death naturally followed.
After Mother's death, Father never remarried. He poured all his energy into training Brother Michikatsu, yet constantly compared him to Brother Yoriichi.
[If only Yoriichi were still here…]
[If it were Yoriichi…]
[If Yoriichi had been heir from the start…]
I watched as Brother Michikatsu grew ever more silent, bewildered by Father's behavior.
When Brother Yoriichi was here, you called him an ill omen. Now that he's gone and Brother Michikatsu stands before you, why can't you acknowledge his efforts?
Later, I understood—this was a flaw in human nature: what is lost always seems the most precious.
...
Life eventually settled into calm. At sixteen, Brother Michikatsu became head of the Tsugikuni Clan. He married, had children, and grew into a formidable warrior.
I was fourteen then. Aside from my refined ink paintings and calligraphy, which earned me the title of "young prodigy," I had little to offer. My swordsmanship was shallow, and in matters of trade or diplomacy, I was often mocked as a fool. After all, Father couldn't stand to see me excel—he would think I coveted the Tsugikuni family's inheritance.
But Elder Brother Michikatsu was generous. He told me I was his brother, free to pursue whatever I wished. Even if all I could do was paint and write, I was still his brother, and he would be proud of me.
What a gentle, tolerant man he was—just like Brother Yoriichi once had been.
When I turned sixteen, I saw Brother Yoriichi again. He returned with Michikatsu to honor our parents at their graves. They said Michikatsu had been ambushed, and Yoriichi, passing nearby, saved him.
After that, Michikatsu changed. He entrusted everything to me, even leaving his wife and children behind to follow Yoriichi. He said he would join Yoriichi to hunt man-eating demons.
But such creatures couldn't possibly exist… could they?
In my doubts, I took over the clan's affairs.
...
Stories soon spread of the Tsugikuni brothers slaying demons. I worked harder to manage the clan, and fortunately, I had some talent for it. After a year of decline, the Tsugikuni Clan regained its vitality.
Two years passed after my brother left.
I met Michikatsu again. This time, his face bore the same vivid flame-like mark as Yoriichi's. His features had matured, and he carried a dependable air. Yet I dared not approach him as before.
For my eyes clearly saw it—a faceless yet distinct shadow looming behind him, made sharper by the moonlight.
[So you've noticed. As expected, you've always been perceptive.]
[…Brother?]
[I am no longer Tsugikuni Michikatsu. I am Kokushibo, a demon far stronger than any human.]
[But… Brother, weren't you a Demon Slayer?]
[…Not anymore. I came back to sever the ties of my human life. This weak clan only holds me back, keeping me from advancing.]
I watched as Michikatsu drew his blade. The snow-white edge gleamed coldly as he pointed it at me.
So that's how it is.
I felt sorrow, but I didn't resist. Closing my eyes, I waited for death.
[…What are you doing? Why don't you fight back?]
[When Father was alive, he told me that if necessary, I must give everything for my elder brother. That is the duty of the third son.
Since you returned not as Kokushibo, but as Tsugikuni Michikatsu, then after you kill me, I only ask you to spare the innocent members of our clan.]
But the strike never came. Instead, I heard footsteps retreating.
Opening my eyes, I saw only my brother's back, walking away.
[From today, I am no longer your brother. Pray no one crosses me on the night road—I will show no mercy.]
Watching Michikatsu step further into the night, I clenched the lantern in my hand and couldn't hold back my voice.
[Brother!]
[…What else do you have to say?]
[After you leave today… I will no longer acknowledge you as my brother.]
[…It doesn't matter.]
As he stepped out the gate without a trace of hesitation, I knew—Tsugikuni Michikatsu was gone. Now, only the demon Kokushibo remained in this world.
...
With grief in my heart, I wrote to Brother Yoriichi, intending to tell him everything.
But just as I finished the letter under the moonlight, a handsome man in a black kimono appeared. Behind him trailed the same faceless shadow.
[As I thought, he still couldn't sever his human ties. Since that's the case, I'll help him.]
In an instant, the Tsugikuni Clan was annihilated by that man.
Lying in a pool of blood, I realized—those faceless shadows weren't human.
They were demons. And they truly existed.