How do you keep from falling asleep during math class? Well, fall in love with your teacher of course! That’s exactly what’s happened to the school stud, Subin. He’s a guy who could have any girl he wants but Ms. Lee is the one he’s after. However, because of a big misunderstanding, he’s suddenly expelled from school and that seems to be the end of that. But years later, pulled by both guilt and curiosity, Ms. Lee finds Subin once again. She wants to make things right and finally get closure on the past. But seeing each other in person again seems to reignite a spark within them... Will what was once forbidden become the start of something steamy…?