The Legend of Arang
It helps to understand this movie if you know the South Korean "Legend of Arang," which appears (untranslated) at the end of the movie:
Arang was the daughter of a local official, and was murdered during an attempted rape orchestrated by a servant (the rapist) and her nurse, who was supposed to protect her. As the story goes, Arang died rather than be raped.
The servant buried the body, and her father--assuming Arang had been kidnapped--searched far and wide before retiring, brokenhearted, from his post. Each of his replacements died after their first day in office, however, until one young man had a dream before assuming the job: a beautiful woman in white appeared in the dream and told him her (Arang's) story, and how each of the man's predecessors had died of fright upon seeing her ghost. This man was the first "good man" and thus did not die--wouldn't he solve her murder and bury her body properly?
The new official awoke, got the nurse and servant to confess to the rape/murder, and then dug up her body, only to find it had hardly decomposed at all. There is currently a monument to Arang in S. Korea, and many South Koreans are aware of her story.
That helps them understand the movie better (even if all the parallels aren't perfect), but doesn't help Westerners much, especially when that final tale goes untranslated at the end! This is more the fault of Tartan Asia Extreme and their subtitlers than it is the fault of the moviemaker, but it's a pretty gross oversight, regardless.
Hope this helps people get the film. Still not a great movie--more a mishmash of a lot of Asian horror staples, tacked on top of a familiar S. Korean legend--but at least it's more comprehensible with this backstory.