Gyeong-ah works as a caregiver and lives alone. The only one she can rely on is her daughter, Yeon-su, but it's hard to see her after she moved out on her own. Meanwhile, Yeon-su, who is suffering from her ex-boyfriend, Sang-hyun, argues with him again and visits her mother’s house. After Yeon-su left, Gyeong-ah receives a shocking message from a stranger.。三年前,陆菁菁因救下重伤的太子,太子为报答陆菁菁救命之恩,迎娶陆菁菁嫁入太子府。陆府嫡女陆玉儿见身为妹妹的陆菁菁即将成为人人仰慕的太子妃,心生嫉妒,冒名顶替。