Cenon Cercyon, son of a Marquis family in the north of the Grand Empire. He was a child that Isaac had seen more than a couple of times, though he didn't really remember him that well.
There were times when the young child would run into the princess in some manner or another, whether it was during a friendly competition the empire hosted without them as participants or just normal excursion and social events.
Since then and all the way to their enrollment in the academy, Princess Cassandra and Cenon Cercyon have been going throat to throat with each other for reasons more than one.
At the crux of it all, though, was a simple desire for proving one better than the other. They had already duked it out in a round of rock-paper-scissors more than once in the academy.
Good family, Isaac personally had met Marquis Cercyon during the event in Poseidonia at that. Good looks, good personality, and good manners.