These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Foe Yay: Very much canon with Julius's interest in Ludwig.
Fridge Logic: So Queen Amalberga and her son look exactly the same. The King is married to a woman who looks like a strikingly handsome man. One has to wonder what that means...
That he wanted the throne so badly, remember, he married into HER family.
Ho Yay: Subtext between Ludwig and Wilhelm. This is a Kaori Yuki manga, after all.
Moe: Cinderella!!! Also according to the Otaku prince, blond Albertina. Oh, how wrong he is...
Moral Event Horizon: After Ludwig manipulated Lisette into murdering her parents for no good reason other than jealousy over Wilhelm as a child, it can be kind of hard to cheer for him no matter how cool he was in the rest of the manga.
Could be a case of Karmic Death considering that Lisette's parents had sold Lisette to prostitution quite a number of times for money. Consider how young she was before she DID kill them.
Real Women Don't Wear Dresses: Not in Kaori Yuki's world. Lisette always wears a dress, Amalberga wears both a military outfit with a skirt and a royal dress, both are psychopaths, but unfeminine? Never!