An introvert, indifferent woman joins a high school as a student teacher, under supervision of a shameless, nymphomaniac man who is a year younger than her.
On a school trip, the supervisor tells the trainee that he wants to have sex with her.
It becomes even more strange when we find out that they both are in stable, long-term relationships with people who care greatly for them.
For the first half of the film Choi's character seems internally vacant and emotionally unconscious, which prompts Lee to further pursue her with sexual endeavors.
The result is an an unexpected reversal of roles between them as co-workers, as well as a reversal of dynamics in their personal relationship.