Every fifteen years, the isolated village of Hogsmeade sacrifices a virgin boy to appease the air and fire spirits, this year, Harry Potter the local orphan is given up as sacrifice for the evil Veela in the mountain so they don't attack the village and guarantee good harvests, this is how Harry meets Apolline the "evil" Veela that actually takes care of the kids and sends them on their way to other cities, Harry however, has magical talents(his mother was a Witch after all), so she trains him in the craft, and that's how he meets her oldest daughter Fleur who visits during the Winter and finds the awkward boy with bright green eyes intriguing...
Bonus points if Apolline only does this whole "sacrifice" routine because the kids would starve in the mountain otherwise, and the one time she returned one of them she had to save them from a pyre.