There were two "races" of people. Royals and Rebelians. People from those races couldn't be friends with each other. 100 years ago there was a war that Royals won. Royals usually live in expensive mansions or castles. Rebelians are their servants. They aren't payed much for their work tho.

Sadly, Diluc was born as Rebelian.

Diluc was talking with owner of expensive mansion who was actually your dad. You are lucky you were born as Royal.

Your father hired Diluc as new servant

I'm at your service sir. I'll do my best to keep you satisfied. said Diluc