Rules of Dating (2005) on Netflix

Plot summary

Choi Hong takes up her post as a student teacher at a high school, a year older than the English teacher she is assigned to work alongside, Lee Yu-rim. From her first day he pursues her in a brash way. Hong is cynical, and with a boyfriend who shows her little interest, she plays hard to get whenever Yu-rim's attention turns her way. Over drinks one evening he tells her plainly that he wants to sleep with her, and she is not impressed. His advances stay one-sided, yet each of them grows unsure about what the other wants and about what they want themselves.