The Little Prince Consort of the Underworld

My girlfriend's surname is Yan. She's tall and sexy, with a sweet face, and her family has an ancestral mansion in the Underworld. Her father oversees the Book of Life and Death, with the fates of yin and yang in his hands. I work as a liaison in the mortal world. My girlfriend gave me a phone filled with ghostly messages. Complete missions for rewards, and, best of all, extend my lifespan. Skr.