During the first season, fans joked that Lelouch's maid Sayoko was secretly a ninja, explaining the occasional flashes of competence seen behind her quiet exterior. Between seasons the staff acknowledged the joke, and in R2 it's revealed that she is in fact the heiress to the Shinozaki ninja clan.
The former 17th heir to the Imperial Throne, Lelouch vi Britannia. It's been a long time, hasn't it, my errant son?
Lelouch: How dare you...!
Suzaku: You won't use your Geass.
Suzaku: Your Majesty, I have a request. Please, sire, allow me to join the Knights of the Round, the ...