The Bewitching Hour
The Jinchuuriki boy hides behind a tree, wide eyes peeking past the trunk. The kodama of the old, hulking she-oak silently giggle at the display, aware that he cannot quite sense them yet.
“Who are you?” He asks, afraid.
The spirits of the forest titter and jeer. She smiles and says, “Yokai.”
Wherein a semi-si/oc gets reincarnated as some mythical japanese spirit instead of a badass ninja and proceeds to fuck with the plot. Features kidnapping small children, ancient mythology, and being a menace to ninja society.