"Crown Prince" is a riddle solved as "Stud Horse"

"Justine, jealousy is unbecoming!" At the end of lunch break, in the courtyard of the Royal Noble Academy where many students were passing through, Crown Prince Alphonse sternly told his fiancée, Justine Sharanton, Duke's daughter, off for her behavior toward his companion, Juliet Fortress, Baroness. Alphonse's left arm remained held by Juliet. ...This is a story that begins with an introduction like that, and you can pretty much guess what kind of tale it is!