His Majesty

The unnamed boy who takes Luca's place in his absence. He is extremely loyal to Luca because His majesty's life was saved by Luca. He is well versed in combat, notably in swordsmanship, due to being a kidnapped and forced to be a child solider. He does not know if Luca is alive, but chooses that it is his duty to protect the Scarlet Chair, until Luca returns to claim it. It is later revealed that his name is Saki.