My idea.

There is a witch who was in love with an elf prince, but that prince was in love with someone else, a woodland elf known as a ranger, a mighty warrior that fights in the king's army when called upon. (Like a fantasy robin hood shin-dig) As revenge, the witch casts a spell and sends this woodland elf into the future. Now, this elf is dressed up in what anyone today would think was cosplay, so she doesn't cause a disturbance. Confused and on edge, the she-elf wanders the streets of New York, curious and afraid of this strange world when she comes upon a human boy. The human boy gains her trust, and the two of them go on an adventure to return the elf to her time. (The two fall in love and either the boy goes with her to her times, or she stays in the future)

Elf x Human

(Roles can be switched so the elf is male and the human is female. Also willing to do in anime or real.)