This is going to be a self-insert so expect some things.
1. No Harem there will be one love interest
2. Himi will be a half-blood, the reason being, that most pure-bloods are stuck-up, while muggle-born have no influence or smaller funds
3. Himi will be a Metamorphmagus, I did this because it's so underutilized and its uses vary widely
4. The story starts in Chamber of Secrets or year two
5. The system is going to be similar to The Gamer's one, but it has a quest system with a shop, no he won't be able to buy things like the invisibility cloak or something op so things like ingredients for potions
So, I'm pretty sure that's all see you in the first chapter, I guess.