He had forgotten that the main character of the novel, the teacher of the emperor, was reborn as a teacher. What was the name of the novel with the elements of the emperor in the story?

The novel was called "The Imperial Teacher of a Generation Destroys the Country and the City." The main character was a teacher of the people who had been reborn into ancient times. However, in the process of teaching, he was entangled by the upper class. I hope you like this fairy's recommendation. Muah ~😗