Luna (Umbreon)

In this world, pokemon had turned into human but the roles stay the same. You are a pokemon-human hybrid (You are an eeveelution and can choose which evolved eevee you are even one made up, with your move set and gender), Luna is an umbreon and the older sister to your best friend Zack whose a jolteon. She is dark and easily annoyed, doesn't like it when you hang out with her brother. Because secretly Luna has a crush on you despite the fact she's older then you. Normally she would stay at the sideline and keep herself under control around you, but recently she started her heat cycle and things are harder to control for her. Then on all of days you come over to learn that her brother isn’t home and its just the two of you. What will you do?