This is the story of a "girl" with a body that is "absolutely immortal."
Crossing the long river of time and enduring ages no ordinary person could survive with an endless life, this is a story with no end.
[Single, no romance plot.]
P.S. The current world includes Inuyasha and Sekiro: Shadows Die Twice. Others are undecided.
There may be Nura: Rise of the Yokai Clan and Hell's Paradise, or there may not be. It depends on how things develop.