Regis knew it was an illusion. He'd only ever seen Princess Charlotte from a distance; only heard her voice when she spoke to the crowd. Sure he was good at reading people, but he knew she'd be wearing the perfect mask.
The problem is that he's in love with the illusion, and it won't go away.
So he embarks on a quest: to win the annual fighting tournament where she awards prizes and assumes - just assumes - that he can forfeit the monetary prize and instead ask for a week to get close to her, to get to know the real her, to once and for all shatter the illusion.