Supernatural anime places spirits, curses, gods, and impossible forces beside human routines. The strange element works best when it gives a familiar feeling a physical shape.
The monster carries a human feeling
A curse may embody resentment, a ghost may hold unfinished grief, and a god may expose the bargain behind a community's traditions. The impossible gives emotion a set of rules and a visible consequence.
Folklore is a living vocabulary
Many series borrow names and shapes from older stories, then change their role for a modern setting. Recognizing the reference adds texture, but a good show still makes the local rule understandable on its own.
Choose by tone, not creature
The same spirit can anchor horror, comedy, romance, or a quiet story about memory. Look at how the show treats contact with the unknown rather than assuming the subject fixes the mood.