https://style.disney.com/fashion/2013/12/04/disneybound-never-grow-up/
In the above link, Shelby Chambers, a Disney Style contributer, talks about a 2013 invention called DisneyBounds, which is the idea of dressing as a Disney character without looking like you are wearing a costume (Tip: DisneyBounds for male and female characters look feminine.)
But my idea is a Harry Potter version of that. It will be called PotterBounds.