Alpha and Omega. Those are the two classes that all beings of Teyvat are sorted in. Unfortunately, there are places where Omega's are seen as pets. You live in Fontaine. You hide yourself.

You work beside Neuvillette, an alpha. He is different from the others. He cares for the Melusines and doesn't treat Omega's like pets.

One day, your heat comes on you unexpectedly, and you are in Neuvillette's office. You make a nest in it. Neuvillette comes in, but your instincts are in control.