He gets assigned 27 years old student teacher Choi Hong (Kang Hye-jeong), who he instantly falls in love with.
Although he has a girlfriend for about 6 years Lee tells Choi straightforward that he wants to have sex with her.
And if the two people dating are already involved with other people, then that's a whole new batch of complications to add to the equation. Director Han Jae Rim received the Best New Director Award at the 43rd Daejong Awards for his work in this unconventional tale of lust and love.
The film centers on a dedicated student teacher named Choi Hong (Kang Hye Jeong, from Old Boy) who finds herself being propositioned by English teacher Lee Yu Rim (Park Hae Il, from My Mother, the Mermaid), a man who just so happens to be the person in charge of her class! Not one to mince words, Yu Rim simply asks the unsuspecting Choi Hong to have sex!
To make matters even stranger, Yu Rim already has a long-time girlfriend. The posters for Rules Of Dating include the two protagonists smiling in an oh-so-sly way that might suggest this to be a relaxing romantic comedy. In fact, it poses quite a complicated question Should love and sex be the same thing?
Lee gets to know a lot about Choi's past, the reason why she is so rejecting and why she still isn't a teacher at her age.
The relationship is ill-fated from the beginning, but when rumours about the two are spreading at school, problems just start to pop up.