In fantasy novels, men and women switching genders was often called a gender changer or a sex change operation. This type of novel usually involved topics such as gender identity, gender discrimination, gender violence, and the lives, experiences, and rights of transgender people. The theme and plot of this type of novel were very rich. For some reason, the male and female protagonists swap genders and begin an unusual life journey. They will encounter various challenges and difficulties, need to overcome identity barriers, learn new languages and cultures, and gradually adapt to the new gender identity. 2. The hero and heroine have deep feelings for each other, but due to gender differences, they often encounter various obstacles and challenges, such as gender discrimination, family resistance, social rejection, and so on. They needed to overcome these obstacles and finally come together. 3. The gender change between the male and female protagonists involves magic, myths, legends and other elements. They can achieve gender change in some way and obtain new abilities and powers. This type of novel usually attracts a lot of readers 'interest because they involve real-life issues of gender identity and sexism. At the same time, they can also trigger readers to think and reflect.