It's going to be random, so I think you guys need to (keep on) check  this chapter and look for updates, cause any terms that you probably confused with will be explained here. (Or you can ask me here)

Dictionary:

Ah: Title that is given for elites by the king to normal people that he trust and care the most. It's the highest title that a common people can have.

ChuilChoi: Designation of the king (in the regin)  (of Chuil Kingdom)

Im: aunty 

HanYang: designation for the successor Yang. (of Yang kingdom)

Yang: it’s a title like Prince or Princess, given to the royal blood. (of Yang Kingdom)

YangKwon: Designation of the king (in the regin)  (of Yang Kingdom)

Notes:

The setting will be more detailed as the story flows, but overall, the time is probably set on old days where there's no modern technology and stuff. I myself didn't imagine them wearing Korean traditional clothes tho :|

* is to indicate an original character.