watching Elemental, and do I get the premise correctly: a race of living fire, which is by nature deadly dangerous for all living and non-living things unless controlled tightly, demands equal rights and accommodations in a city built for harmonious life of water, earth, and air?
o m g, they literally left their precious original fire country with their lovely "traditions" because they wanted more profit in the big city 
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spoilers
millennials writing this movie don't understand that fire parents wouldn't have any problems with their girl not dating anyone: they'd arrange a marriage
and were she to date someone, moreso someone out of her caste would spell death not for her boyfriend, but for her
I dunno whether they will mention any history lessons of this world, but I bet water, earth, and air were living in peace until fire nation started a war and forced everyone else onto the last remaining piece of land where they established a new city for every persecuted element...