The Scholar Who Walks the Night (Bameul geotneun seonbi)

Sinopsis

When Jo Yang Sun is driven out of house and home after her father is framed for a crime, she is forced to crossdress in order to make ends meet as a bookseller, where she meets Kim Sung Yeol, a handsome, but mysterious scholar who is actually a vampire. Meanwhile, an evil presence at the royal palace stops at nothing to keep the Crown Prince from claiming his rightful throne.