Idgi, why does she need to hide her identity?

Idk maybe because she is the princess of enemy country and they are currently on war?

I’m pretty sure her country isn’t the one at war with the emperor’s tho? Or did i misread? I haven’t read this in a while so I don’t remember ahaha ╮(￣▽￣)╭

they are at war

i thought her brother was invited though??