The King's daughter is a Princess (doh!).

...Aaaand this is the only page I originally wanted to include. To further populate the "Dark Side of the Horse" pool. But then might as well include the other pages too, especially the ones that help establish the background (The Trainer-King Halo relationship).

Ah that would explain one of the random interaction in the game, where King is apparently teaching Princess how to do the ojou-sama laugh