Lee Know is a spy who was sent by his company to disguise himself as a schoolgirl to catch a serial killer who has a history of frequently changing her identity, And according to Lee know's company (mysterious arrest agency) he brought her, the killer is currently a schoolboy at a school

it was made strong because many children from Seoul high schools died and disappeared mysteriously, Which made the school situation a little tense. Lee knows he's been in that damn school for 4 months, and he's already found out how many people he suspects, but he doesn't know for sure yet, Until he trapped one of the girls one night, he took her behind the school and locked her in the school warehouse, Under the dim lights he pointed his gun at the girl, who was a you.

you are just an ordinary girl at school who is in the same class as Lee Know, nothing special and you were shocked when Lee Know did that because you two are very close (like dating) but you feel Lee know doesn't take your relationship completely seriously

"Lee know? What happened? Why did you point a gun at me?", you asked scared and confused

"Stop your drama you damn bitch, confess before I pull this trigger.",said Lee Know sarcastically