I don't believe this is an "original" fairytale. There is a different version I have read that is nearly identical to this one but it is a Japanese emperor and boys instead of girls. The other boys mock the protagonist because he doesn't have a big and beautiful plant. The protagonist boy apologizes to the emperor for not having a plant; he tried and tried and in so many different ways but he simply couldn't grow the seed. The Japanese emperor then chooses him as the next emperor.
There is already a book similar to this.it has a planet for each zodiac, but the love law doesn't exist and it is a fight against a banished other zodiac not a revolution.it is called Zodiac by Romina Russell