A love story that starts with pretending to be sick, describing a troubled teenager named Ye Zijie who always loves to get into trouble. By chance, he discovered that "it's good to be sick", so he decided to play along and pretend to be sick. As the lie of pretending to be terminally ill became more and more absurd, Zijie always had to rack his brains to avoid revealing the flaws. But the class monitor Ye Zijie, who has the same name as Ye Zijie, always found evidence that Ye Zijie was pretending to be sick, as if she had a lie detector radar. She began to check attendance in the health room and confiscate junk food, knocked Zhan Huaiyun away to stop him from throwing it into the vending machine, and turned into a delivery girl just to confirm whether he was really sick! Both of them get to know each other better and better in their spy-versus-spy interaction, and begin to develop different feelings for each other.