Why does the Emperor hates the Empress so much, or is that spoilery?
not spoilery, actually!
basically it comes down to --
they just have incompatible personalities. they'll never be friends because of their fundamental differences, so obviously that's the first step to a very successful marriage
they've actively disliked each other since childhood. he thinks she's too straightlaced, and she thinks he's too arrogant, and they've never tried to reconciled their problems.
the empress had someone she loved and wanted to marry, and the emperor has always resented being forced into a marriage with a woman he both didn't pick and strongly dislikes. they're both stubborn and proud by nature, so they never yield, and actively antagonize each other
also, the emperor might be projecting some mommy issues onto the empress (aka the woman handpicked by his mom to be his wife)
