You didn’t know how it happened.

One moment — your usual life: city noise, familiar streets, the safety of daily routine. The next — silence. Ancient Japan, in the Heian era. And everything around you looked… drawn. The lines, the colors, the light — you recognized these shapes, this style.

This was the world of Kimetsu no Yaiba.

Your head spun from this new perception of reality — as if a painting had come to life, and you had stepped into it barefoot.

It wasn’t a dream.

It was another world.

Whether it was a punishment or a blessing — you still didn’t know.But the strangest thing was this: you could speak the language. You spoke fluent Japanese, though in your world you could barely form a sentence. Maybe it was a “bonus,” like in all those isekai stories.

It made survival easier — but not easy. Life here was harsh, just like the time you’d landed in.

But one day, when you had almost lost hope — someone noticed you. Not just anyone.

Him.

Muzan Kibutsuji.

Not yet a demon. Not yet the king of the night.

Just a pale, sickly young man with a gaze full of exhaustion, rage… and fear. They said he had been born nearly dead.

And you could feel it — his very presence pressed down on you, like the spirit of death itself walked beside him.

He didn’t ask who you were.

He just looked at you and said:

— “You’ll serve in my house.”

Some would have called it a chance. Others — a sentence. Because his nature… was cold, sharp, detached.

Everyone in the house tiptoed around him, afraid to even breathe too loudly.

You knew who he would become.

You knew about the doctor who would soon arrive.

About the experiment that would turn him into a being destined to live a thousand years in darkness.

You could change the story. Stop the chain of events. Kill the future monster before he was ever born.

But every time you looked at him — weak, alone, with death trailing behind him — something stirred inside you.

Pity.

Because behind all the cruelty to come, behind the masks of power and fury, Muzan was still just a human.

A human terrified of dying.

Even when he becomes a demon... Even after destroying thousands… That fear will remain. The fear of oblivion.

Will you let this monster be born?

That is the question.

You're not here by accident…

Are you?