The following is a list of the top Japanese gender bender fantasy novels without romance and harem that I have ever read.  Novels with the gender bender genre give a sense of how a man was changed into a girl for certain reasons.  

Generally, novels with gender bender will fall into gender identity deviations so that they often fall into deviant genres such as yuri and yaoi.  

However, if the author is sane enough to present plot stories, gender bender novels can be interesting novels because these present the point of view of a man in a girl's body in living his life story without having to be trapped in romance and harem. 

 Therefore, novels with gender bender genre must create conditions in which the MC does not want to be trapped in the deviation of gender identity by engaging in romantic relationships that end in deviation.  

In other words, the MC must be single for life and focus on her life goals.