Kimi to Boku no Saigo no Senjou, Aruiwa Sekai ga Hajimaru Seisen
Kimi to Boku no Saigo no Senjou puts a tech empire and a magic kingdom into a war that has been going on for hundreds of years. It then asks what happens when their best fighters don't really hate each other. Iska is a genius soldier from the science-heavy Heavenly Empire, and Aliceliese, the "Ice Calamity Princess," is basically a princess on the magic side. They should be killing each other on sight, but instead they keep running into each other and realizing that they are both fighting for the same dream: real peace. The chemistry is instant and dangerous because if they say they respect each other, they could both be killed for treason. The action-packed battles and the interesting star-crossed relationship between two people trying to build a bridge between worlds that have been at war longer than either of them has been alive are what make it work. It's about keeping your humanity when everyone else thinks you're a weapon.