Eun is a girl who has a sort of... "Split personality". Except the problem is, her "other self" is a demon. She switches between her normal self and her demon self like a mood-swing. (AKA, her demon self is very rebellious and can sometimes be rude, sassy, and is very violent.) In our-world standards, she's Japanese/American. I kind of want a last name that could hint at her demonic self, but that's not mandatory.
Dernier is a boy who's into fashion and design. He also collects rings. (He wears 1~3 per finger) Unlike Eun, he's actually relatively normal. Short hair that spikes out near the tips,long button-up shirt with a belt, pants, a fur collar, et cetera. In our-world standards, he's German. No references necessary.
Super High-School Level Funky Justice - Twouko Funkawa