@HiAndHello I slightly disagree. Yes, divorce is thrown around easily in these kind of stories, I think that some people don't view it as sacred or heavily a oath as you say/and how easily it is to get married for some. Also limited pages and plot purposes might not have allowed this girl talk to get as detailed as it might've been irl but honestly I would be okay if Maize wanted to get a divorce. They exchanged oaths yes, but don't forget that the whole premise of their relationship is a lie. He's been lying to her since Day 1, would've lied to her and manipulated her more if she wasn't the saintess and had the power to see through his illusions/mind magic whatever. His whole personality is a facade he shows to her that he thinks is her ideal lover. Her whole job and all the effort she spent on it was a big fat lie.
As the main couple, I'm betting even if they were to get divorced, Izu will just court Maize openly without deception and then they get married again......somewhere between the subplot of the soldier dude and the fate thing going on.