Tide Meng and her mother have been living in the United States, and Yi Yun is Meng'er's good friend. Her mother wanted her to go back to China to go to college, so Ximeng, Yiyun and Mulan returned to China together. They colluded on the plane and added a surname in front of Yuner's name, which was Ximeng's surname. Shen asked her to pretend to be Heyang's younger sister and go to school to trick people.
So
He Yang followed their plan and deceived his best friends in the school.
The sister who was originally very smart in He Yang's mouth turned into
Yoona is this beautiful stupid princess.