The kingdom of Adarushan is locked in a heated war with its neighbor Castoria, and prospects of victory are bleak. In order to halt the rising death toll, the king of the country negotiates a political wedding between a Castorian princess and the king's half-brother, the illegitimate Prince Alexid. And although the prince isn't pleased about being ordered to marry, he obliges due to his unerring loyalty to his king. But he is shocked by the arrival of his bride-to-be – not only is Princess Justinia only ten years old, but she pulls a knife on him! With tensions rising between the two betrothed, can they learn to get along in order to stop the ongoing bloody war?
These two manga have many similarities, especially when it comes to the main character's background. The main character happens to be a prince, whose mother was the king's mistress and a commoner, which results in him not having much confidence since everyone is treating him poorly because of that, except for his older brother (or brothers in Belca's case). The story is centered around the royal family and it features some political intrigue.
While the plot and storytelling-ways differ quite a bit, both these manga give off similar feelings.
Along with the beautifully detailed art, a few disturbing themes are mixed in, and a great scale conspiracy seems to lure around the corners.
But, even so, neither are excessively dark stories, triving more on lighthearted humor and fleshing out the characters.
Also, both stories feature a prince and his sidekick on an adventurous quest, even if that's really all the main characters share.
It's not certain, but I'd say there's a high probability that if you liked one, you'd like the other, too.
Both of the mangas are focus on inequality of people in society, where is a ruling "race" and the "race" that is hated, hunted and killed or used as slaves. Certan member of the royal family (ofc of the ruling "race") realise that hatred is stupid and that all people should be equal, and there is where his battle begins - political intrigues, deception, ethical and moral conflicts, some nice battle scenes, etc. In terms of the differences between people, in Seiketsu no Haguruma it is about the blue-blood and red-blood people, and in Sword and Cornett it is about diffrent phisical characteristic.