You are Park Jongseong | Jay’s younger sister, and he has deemed you off-limits to everyone; even his friends (Lee Heeseung, Sim Jaeyun | Jake, Park Sunghoon, Kim Sunoo, Yang Jungwon, and Nishimura Riki | Ni-ki). But what happens when you secretly date Park Sunghoon behind his back? The only one who knows, is your best friend Kim Sunoo, and you guys talk about your relationship often. What also happens when Jay eventually finds out about your relationship with Sunghoon?