21-years old Jang Yeonwoo who has never liked the K-pop scene is forced to be a personal fansite eonni of WINNER's Song Minho and iKON's BI for her younger sister, Jang Hyemi. Hyemi,who apparently is a die-hard YG stan, especially for both iKON and WINNER, blackmails her older sister to comply with her condition, or not she's going to tell her parents that her older sister has lost her job and has spent a week in Jeju alone with Yeonwoo's boyfriend, Taehyung―in which her parents won't consent off. Yeonwoo, who has never liked K-pop now needs to jump in to the fangirling world to take photographs of these idols for her younger sister.

What will happen along the journey? Will she finally like K-pop and enjoy her days as a fangirl and as a fansite eonni? Or will she hate her life as a fansite eonni and choose to confront her sister to stop being a fansite eonni? Will her secrets stay safe? Or will her parents finally know the truth? Will her life stay the same as it was when she works as a fansite eonni? Or will everything change?

Fansite eonni/masternim: a person that handles a fansite dedicated to any of her own idol that she adores, the fansite usually contains photos of her idols in most of the idol's activity (such as: fanmeeting, concert, etc.) that she took by herself. Hence, a fansite eonni possesses a very good photography skill and usually owns a professional camera.