Demon Slayer: Am I the Ancestor of Zhuoyue?

Awakening my memory, I found that I had become an inconspicuous little person before the main plot of Demon Slayer: Kimetsu no Yaiba started. Did you find that you seem to be the ancestor of Yuyue? I'm no longer a human being! As an ordinary young man with a weak body, he learned the ultimate goal of coming to this world when he returned home: Become the Ghost King... When I arrived at the door of my "home" in this world, I met the legendary Third String...