This one needs no introductions because this is 1/2 Prince! It is set in a virtual MMORPG setting but the gender of the main protagonist has been switched in the game (which is, technically, not possible. – A certain GM in the novel).
The manga adaptation is also very good, and happens to be my first exposure to this story. Either way, you’ll surely enjoy both formats should you pursue them.
You may access the ePubs on the link below.