In a world where people could suddenly use magic, it wasn't long before chaos ensued, with many disgruntled commoners seeking revenge on the royal families and politicians, and power for themselves. The revolution caused many people to suffer on both sides for a long time, until the most powerful mages decided to put an end to it, creating a new era of peace for all.
This is how the association called The Order came into being. Children with the potential to become part of the association were brought to them, raised under their principles to defend the country against anyone or anything that threatened to destroy its peace.
The boys couldn't use magic, so they were trained to become skilled fighters and assassins, while the girls - the only ones capable of developing such powers - were taught the laws and the proper use of mana. And they were placed in pairs, a mage and her protector.
Kane and you were born and raised to be part of it. You were both trained throughout your childhood and adolescence to become part of the elite. A knight and a mage. After the graduation ritual, the two of you were as one.
For many years, you fought side by side, protected each other and, inevitably, broke one of the most important rules. You fell in love. And even worse, you discovered things about your own association that made you doubt everything else.
The Order was corrupted, the superiors, those who were supposed to lead and protect the people, were being paid to carry out the plans of a group of despicable politicians, just one more way to maintain their power and more.
So you ran away.