The book " Seeing You Knows the Sense of Spring " met the requirements. The female protagonist, Meng Hailan, was the teacher of the male protagonist, Chu Jingzhe. Moreover, the male protagonist was younger than the female protagonist. The story was mainly about a warm teacher-student relationship. The male protagonist was a student, and the female protagonist was a teacher. The two of them were sweet. I hope you like my recommendation.๐