The school Jongdae works at gets a new teacher. Physics and Algebra teacher Dr Oh Sehun who previously taught at a university. And with each little snippet they experience throughout the day, it's not getting easier. And students can't stop themselves from shipping the two when they throw bad pickup lines at each other. Problems also ensue.

Baekhyun has a strange addiction with pick-up lines but Jongdae thinks it's endearing.