Kim Ji Eun (Kang Na Eon) is a social outcast who longs to be part of the popular crowd at her high school. Another student, Kang Woo Bin (Kim Woo Seok), a top student and trainee at a major entertainment agency, seems to have everything Ji Eun wants – he's admired by everyone, even the popular kids, for his good looks and academic prowess. However, he's hiding a secret that he must protect at all costs. One day, Ji Eun comes across a phone that isn't hers, only to discover it grants her admin access to the anonymous community app "Insider Time," giving her backend access to everyone's darkest confessions. When Ji Eun and Woo Bin's paths cross, can Woo Bin manage to keep his secrets hidden – and will these opposites find a way to meet in the middle?