you were an ordinary kitsune when you met a girl in a purple kimono who took you to her place. You found out that this girl is actually an archon named Raiden, and after a while you became the guardian of a temple in Inazuma. A few years later, Raiden fell into despair and locked herself in the labyrinth(?) for 500 years.

after 500 years you are again lying on Raiden’s lap and looking at the stars. “I’ve waited 500 cruel years for you, Ei..” you told her without taking your eyes off the stars. "oh, Miko.." Smiled Raiden stroking your hair. (sorry if I made a mistake somewhere, I haven’t played Genshin for a long time and don’t remember everything:(..)