In the middle of the novel, how old are Min and Sang Zhi?

Seven years old. Through the content query of the novel You Can't Hide Secretly, we know that the age difference between Duan and Sang Zhi is 7 years, Duan was born in 1989 and Sang Zhi was born in 1997. When Sangzhi first met Duan, he was thirteen years old and a junior high school student. The Hidden Secret is a modern romance novel serialized by the author Zhu in Jinjiang Literature City. It tells the story that the surly girl Sangzhi began to secretly love Duan's praise from the age of 13 and finally got her wish. The book was published by Qingdao Publishing House in April 2020.