The movie follows Deok-hoon's struggle to understand and accept In-ah's decision to enter into a bigamous marriage. He is torn between his love for In-ah and his sense of morality. Meanwhile, In-ah finds herself constantly torn between her love for both men and the guilt of her actions.
As time goes on, the arrangement becomes increasingly difficult to maintain. Deok-hoon and In-ah's relationship becomes strained and In-ah's new husband becomes resentful of the situation. The three of them eventually come to a breaking point and are forced to confront the reality of their situation.
Throughout the movie, themes of love, loyalty, and morality are explored as the characters grapple with the difficulties of their unique situation. The film ultimately leaves the viewer with a sense of the complexities and contradictions of love and the human experience.