Wei Hou thinks Miyue is the reincarnation of Xiao Ba Xing and doesn't like her. Even Wei Hou once asked someone to calculate the birthdates between Miyue and her daughter Mie Shu. She found Mie Yue was born as Mie Shu, so she especially hates Mie Yue. But Mi Mi is different. At that time, Mi Mi was still young, so she didn't understand the contradiction between her mother and Mi Yue at all. And she fell in love with her sister at the first sight of Mi Yue.
When Mi-Wa was young, her mother warned her from an early age that because she was the first princess, she could not make any mistakes in manners, so she was always told to keep a dignified posture. Therefore, because of her noble status, no one is close to her at all, resulting in almost no friends. When she saw Miyue for the first time, Miyue didn't have any estrangement from her because of her identity, and made friends with her, which made Miyue very happy in her childhood. So she can't care about her mother's wishes and be close to Miyue at all, just to make up for the love that Miyue herself couldn't get because of lack of friends in her childhood.
With the death of Miyue's father Chu Weiwang, Miyue's umbrella in the palace is gone. At this time, Mi Mi has a different feeling about Mi Yue, because Mi Mi feels that she and Mi Yue are playing two roles, one is the giver and the other is the giver. Like a good man, I always appear and help her when I need it. This feeling makes Mi Shu very proud, because she feels that it is a strong sense of charity that can't be obtained from other people, so even though Wei Hou hates Mi Yue, Mi Shu is always willing to help Mi Yue.
When these two roles change, Mi Shu will hate Mi Yue as much as her mother. Therefore, we can see that the more the plot moves back in legend of miyue, the less love Mi Shu has for Mi Yue, and the only thing left is hate. Mi Shu has never been a kind person. She just wants Mi Yue to live by her.