To be more specific, is it possible to romance Kiana at all? And if so, how to get there?
I’m assuming Kiana is just the female version of Kionus—the Lieutenant turned General? I managed to romance him (or her, in your case). I believe the option only appears in the last chapter of the game. You specifically have to pick the option saying that you’ve found yourself helplessly falling in love with them. I believe that sets up the potential for romance. 's what I did. Either way, to romance Kiana/Kionus, you’ve essentially got to start an affair with them. One of you is to be wed to the Prince(ss) so you better have a high Certitude to convince them the affair’d be truthful and all that jazz.