"Guardian Angel" is a hilarious and satirical comedy about ghosts. The story takes place in an old house where a couple lived until the wife's infidelity is revealed and the husband decides to murder her lover. In the process, they accidentally kill the construction worker Ah Kit, whose ghost haunts the place. The couple sells the house to newlyweds Tang and Ma who face a series of strange occurrences. As they settle in, they realize that the ghost is friendly and helpful, even assisting with household chores. The couple becomes friends with the ghost, and she helps them with everything she can. Eventually, the kind-hearted ghost must be reincarnated, leaving the couple heartbroken. The film's hilarious antics suggest that humans and ghosts can coexist in harmony, while humans living together may have issues among themselves.