College student Ke Miantang accidentally enters a novel while criticizing its plot and becomes a minor villainess with little screen time. A system assigns her a mission: play the girlfriend of Rong She, the heir to a corporate group, for 150 days. If she lasts until the original female lead officially appears, she can complete the mission and return to her former life. In the novel, Rong She is supposed to be indifferent to the villainess, but everything changes after Ke Miantang arrives. The young master of Xingyun Group is calm and decisive toward others, yet endlessly indulgent toward her. She desperately reminds herself that she is only a temporary girlfriend and that their relationship is just an act, but he gives all his tenderness and special affection to her alone.