The Demon King.
The progenitor of demons.
Muzan Kibutsuji.
What had this man, who had plunged Tokyo Prefecture and all of Japan into chaos for a thousand years-the one demons called "that lord"-been doing throughout his long life?
Leather shoes stepped lightly across the soft white snow, yet the young, curly-haired man left no footprints behind him.
He strolled leisurely through the mountain forest shrouded in darkness, repeating the pattern of his life.
Searching for the Blue Spider Lily.
Turning talented people into demons to see whether they could overcome sunlight, and if they could not, making them search for the Blue Spider Lily on his behalf.
Infiltrating human society, gathering funds and building connections, then using those connections to search for the Blue Spider Lily.
After Yoriichi Tsugikuni died, everything he did for the rest of his life revolved around the Blue Spider Lily.
The Blue Spider Lily... recorded in the notes of the physician who had turned him into a demon over a thousand years ago, a flower that could let demons walk freely beneath the sun and become perfect beings.
Muzan often ventured into remote mountain forests. These ancient, unexplored places were more likely to produce a miracle.
...A miracle only for him, of course, but that was enough.
Small snowflakes began drifting from the sky again. Muzan emerged from a pine forest and spotted an inhabited wooden cabin amid the deserted mountains.
Ah, people.
He walked toward the cabin. A woodcutter living in the mountains?
It doesn't matter. Whoever they are.
He approached without a sound. Before pushing the door open, he tilted his head to glance at the firewood stacked neatly outside.
The cabin door swung open, and the sound of the wooden latch snapping jolted Kie awake.
"Tanjiro?"
Thinking her eldest son had returned