Guide to be King of the Dead is a Manga/Manhwa/Manhua in (English/Raw) language, Adventure series, english chapters have been translated and you can read them here.
When she opened her eyes, she was in the underworld. Suddenly, she became a possible successor for the position of Lord of the Dead! Ji-hwa, who was once an ordinary job seeker, now embarks on her journey to become the King of the Dead.