If I remember, that has a link with the twins' mother. They said in other chapters that the Princess had more heibi blood than her brother who had more imperial blood. That's why the twins didn't have the same reaction when they met their guardian. But I don't remember very well either ╥﹏╥
Umm, do you guys know whats heibi means which mentioned at ch68. I forgot if they did mentioned it in the story before chapter 68 ╮( ̄▽ ̄)╭