I highly recommend reading An Ember in the Ashes by Sabaa Tahir. It is a fantastic book that tells of Laia, a poor girl in the harsh Martial Empire and Elias, a boy forced to be the kingdoms minion and enforce the tyranny they instate.
Laia is sent to the the Empire’s greatest military academy to spy for rebels in hope that they will help her rescue her brother who was arrested for treason. There she meets Elias the academy’s finest soldier but secretly it’s most unwilling. ” He and Laia will soon realize that their destinies are intertwined- and that their choices will change the fate of the empire itself.” ( front cover).