Im really interested how/why they decided that marrying the princess was the reward for the hero.
1. "Decided by the Royal Family and the Parliament" but the King can't refuse it.
2. Apparently they know that the hero is female and decided to wed their princess for a yuri pairing instead of a prince (there is usually one for succession rights) for standard bloodline/power reasons.
@Nep maybe i translated it wrong, but i used google translate on the source for that bubble to make sure and it said "imperial family" while the chinese said "royal family
as for number two, i assume it was like a bounty, since no one expected a woman to defeat the demon king, it would probably make sense that the reward was set for anyone who kill the demon king and the princess only recently found out about the reward... or something