Who is the murderer in the script of "Wedding Blessing"?

The murderer in the script of "Wedding Blessing" is Qi Ai.

Qi Ai received a text message from an "unimportant private detective" and learned that her sister died due to Liu Tian's crimes. After receiving Liu Tian's text message, he decided to kill Liu Tian. Because in order to understand Song Xiaoqi, Qi Ai read all her books, including "Wedding Blessings", and knew the death of the deceased at the end of the book, and planned to fake Liu Tian's death into a similar death to make him confess.

Full plot restoration:

1. 10:55: Qi Ai received a text message from an "unimportant private detective" and learned that her sister died due to Liu Tian's crime.

2. 11 o'clock: Received a text message from Liu Tian and decided to kill Liu Tian. Because in order to understand Song Xiaoqi, Qi Ai read all her books, including "Wedding Blessings", and knew the death of the deceased at the end of the book, and planned to fake Liu Tian's death into a similar death to make him confess.

3. 11:10: Qi Ai went to Liu Tian’s room and pretended to have some ambiguity with Liu Tian. He covered Liu Tian’s eyes with silk stockings, asked him to sit at the desk, and stood behind Liu Tian to copy. He picked up the fruit knife on the fruit stand next to him and cut Liu Tian's right carotid artery. Because the blood from the carotid artery would spurt forward, there was no blood on Qi Ai's body. Liu Tian first covered his artery with his right hand in pain, and then died on the table.