After Dressing up as a Vicious Female Supporting Character, I Became the Protagonist's Pendant

On the first day I entered the book, I was being divorced by the prince in public. The system prompts: "Host, please maintain the vicious character and slap him!" I slapped the prince with my backhand: "I am only a wife, not a concubine!" The prince covered his face in shock, and the whole court was in an uproar. The system got stuck: "Warning... Detected... Serious plot... Deviation..." I smiled proudly: "I am the heroine!" Until I met the cold and aloof true heroine. When she was in danger, I blocked the fatal arrow for her. System crash: "Host, are you crazy? She is your mortal enemy!" I leaned weakly in her arms: "The plot is nothing..." The system froze and suddenly a cat jumped onto my shoulder. It licked its paws and said: "Congratulations, you have unlocked the hidden plot——"