Different people have different attitudes to love – even those who have not experience it yet do not necessarily share the same views.

Jeon Rinah lives her life recklessly as a mysterious girl. No one knows her real identity. If she gets exposed, then it's game over. Disguising as a high school student, she's actually one of the most youngest undercover agent up to date along with her partner, Lee Hyunwoo.

Everything is going as she planned, but then she encountered a boy who let her life turned around to it's . Is it alright she's friends with...

...Kim Hanbin..?