Shin Hyejeong is the number one spy of FNC Agency, and despite being an orphan and a skilled agent she has a bright and bubbly personality unlike her dark background. One day, she is sent on a mission to keep track of the Vice President's daughter, Kim Seolhyun. Kim Seolhyun, although being the daughter of the Vice President of Korea, is shy and reserved. She doesn't talk to anyone much and doesn't open up to anyone either. Or that was how it was before Shin Hyejeong came around. The two girls create an unlikely bond, but will it be able to stay?