I am really surprised - though honestly not shocked - that more people don't note that the glaring truth of this film is that it's about the invasion of Western capitalism in South Korea. The more SK has Westernized, the more its people have the same problems as anyone stuck in a capitalist grind.
The main character is basically a robot who takes abuse constantly in her job as a customer service agent who answers phones for a credit card company. She handles every call with rational detachment and feigned politeness, obeying the commands of rude and irrational customers who don't see her as a person.
Jina's plight is further complicated by her bottled up grief over the death of her mother. It takes the death of a neighbor, who appears to her as a ghost, and a young, needy trainee at work to reach into Jina's solitary world of work and television.
