SPOILER PLEASE!!! （/TДT)/

Omar, whom the duke blindly trust is the one that gave the ownership documents (which the duke blindly signed) to Opal.
He now has to work off his debt to her to repurchase his duchy.
Later he makes enough money to repurchase the duchy but invests it haphazardly on a piece of land he's not able to develop himself.
Opal's childhood friend is the one that came in to help him out and develop the land.

And who she is gonna end up with?

Claude, her childhood friend.