Angels, Demons, and the Low-Life Demi-Humans

This is a world where Angels and Demons are the superior races and then there are Demi-Humans. The Demi-Humans are a race of those who are half-animal and half-human. They are put at the lowest of the hierarchy of the three races. Depending on what kind of demi-human they are, they may be higher or lower than the others like them. Angels and Demons have been living together despite not liking each other very much. Angels and Demons have a demi-human as a pet, some have more than 1, but most have at least 1 in their household or in their own place. Rikka is a extraordinary person. She is half-angel and half-demon. Being one of the only hybrids that exist, Rikka lives alone and then she is asked to attend the prestigious school, EA (Ethereal Academy). Being enrolled, students are given a demi-human as pets to keep for the rest of their lives. But when 3 charming demi-humans were given to Rikka by magical means, Rikka doesn't know what to do and decides to accept them all despite their different ranks among demi-humans. Rikka doesn't like the attention she's getting nor does she like it when demi-humans are bullied. She hopes that one day, demi-humans would be treated as equals and not pets, but those dreams seemed so far away. She and her 3 new demi-human friends hopes to find a way for demi-humans to be treated equal or be given more rights.