Inhumans were often called odd. Their cultures and ideas were vastly different from the human's, and even their magic followed different rules.
One of these rules is the bond system. All of them were destined to meet someone who would connect them together eternally, and sometimes more than one person. Their first bond is their primary bond, the next is there secondary, and so forth. While not the most common, it was still often that bonded pairs were of different species. Socially, this wasn't an issue, as inhumans were far more accepting than humans, but that didn't mean it wasn't one family wise.
Mixes of two species didn't live very long, usually only what would be considered the "late fourties" for their species. Most were too afraid to try for children because of this.
Mixes of three or more had only made it to a record of seven human years, and that was a single outlier.
Until them. They had lived and thrived, which confused everyone. The three were still alive, albeit one is being mind controlled, his twin has been captured, and the youngest had his memories sealed, but that's another part of the story for another moment.
Another rule their magic followed was not spoken of. It would terrify the humans to know they all had human forms and walked among them. For the all the god's sake, they'd start another damn genocide!
Actually, the ones that did know had already begun that genocide. That's who had captured the younger twin to use his magic like a battery.
The humans are still a new species. They have not yet learned to embrace each other for their differences, so we have tried to teach them. We tried and tried and tried to teach them, but nothing ever seemed to get through to them.
We cannot fault them for their fear, for we were once the same.
We fought each other until we realized a group of humans had turned us against one another to make it easier to kill us. Not all humans were this way, but KuroKokoro was the biggest threat we could ever face. Their magic could hurt us, and that was the cause of our fear.
For a long time their attacks ceased. There was peace among all.
It did not last.
Unfortunately, the main dimension is ruled by the humans, and those who are different are not as accepted, even by the humans who did not hate us.
Since the dawn of time, this world has been locked in this stalemate, KuroKokoro and the humans they were able to corrupt against us. Anything that was not human was their target, even sympathizers were eradicated. We were forced into the side dimensions of the world anytime we were not in our human forms, and many inhumans were powerless against KuroKokoro. Often times the innocent were KuroKokoror's collateral damage, and it had been blamed on inhumans, giving them a horrid reputation when it was not their, nor their race's, fault.
The inhumans see themselves as protectors of all life, and that they were. There are hundreds of villages, cities, and even whole countries who would be long doomed and dead if it weren't for them.
The innocent humans didn't know, and if they never found out, then they wouldn't get hurt as badly.
So the inhumans trained themselves to act human, to look human, and to speak like the humans. After all, since human logic is "If it walks, talks and acts like a duck, then it must be a duck," then it would be easier to protect them from up close.
This is the story of those who fought for our peace. It is not a happy story, no matter how it may seem at times. Far too many people died to give all people freedom.
This is the story of a guild called Fairy Tail, who forced the world to listen and unite. After all, they wouldn't abandon their Nakama, no matter how inhuman they might be.