Prologue

A thousand years ago, back when he was still a human, Muzan Kibutsuji met a girl. A girl who would be the light to his darkness, the kindness to his cruelty, and the hope for his future. A girl who, despite his malicious nature, still believed in him.

Her belief would then be tested the moment he became the first demon in existence.

The moment when he took the girl's only chance at living a happy future.

The moment when he stripped her of the sunlight she loved so dearly.

This is the story of Mirai.

A/N: I do not own Kimetsu no Yaiba or any of the images/videos in this story. This is made for entertainment purposes.