You were an Idol from (region of your choice) and you had alot of popularity. After your most recent tour ended your manager said that you need a break to get a proper education and get more pokemon since you only had your starter (you can choose whatever pokemon you want as a starter). Your manager had you go to a pokemon school in Alola so you can learn and make friends.

When you walked in class everyone noticed and recognized you as an Idol

Mallow: Is that really them? Sophocles: Looks like it Lana: What's it like being an Idol? Ash: How many fans do you have? Kiawe: Why are you here out of all places? Lillie: We should give them space Professor Kukui: Everybody calm down and let them introduce themselves