Disclaimer:
I own nothing that you recognize, and there will be parts in the future that I won't own even if you don't recognize it. But I'll be sure to point those parts out in advance.
Introduction
The Wish Granters were well known creatures in the Wizarding World. Every year, on the night of Yule, they would flitter from house to house, seeking out wizarding children. If a child made a wish when a wish granter was near, and the child had behaved well the year before, the Wish Granter would make their wish come true. Sometimes, when a child had not behaved during the year, the Wish Granter took it upon themselves to reverse the wish, and give the child the opposite of what they'd asked for. If a child asked for another pet, for example, their prized unicorn may disappear. If they asked for a new home, their old home may be destroyed by some manner of natural disaster. But some, rare as they may be, some children got far more than they had bargained for with their wish. If they were particularly good, a wish for a new home might mean their parents suddenly received a promotion at work and came into more money. A desire to have a sibling might mean a household filled with younger brothers and sisters to play with.
Many children wished on this night, and nearly all so-called "pure bloods" did. The Wish Granters paid no mind to such issues as blood purity when making their decisions. A pureblood was equally as likely to get their wish as a "muggleborn". The only quality that mattered to a Wish Granter was purity of heart. So when a pure child made a wish, no matter their status, the wish would be granted with a smile, a flick of the wrist, and a snap of the fingers.
So when one little boy, heart as pure as the gold of Gringotts, made a very special wish, the Wish Granters gladly allowed it to come to pass. That wish? A simple plea, really. Something most take for granted. That little boy, little Harry James Potter, wished for a family. This is his story.