Hyejun, a feisty female bodyguard, is hired by the young Jaehyun, but when she walks into his house, it’s full of… more guards. But instead of protecting him, they're keeping him there. To hide her true identity as his personal guard, she goes undercover by pretending to be his girlfriend. One day, their undeniable attraction pulls them together to share a kiss. Now, as the lie seeps into their reality, having a strictly professional relationship is becoming less of an option.