Years back, when Chaerin was just a child of seven years old, her family got attacked by a rogue. Her father bravely fought against the invasors of the humble home, but she heard he got killed trying to protect her, her mother and sister. Heard, because she never saw it happen or even saw him dying. 

 

They ran through the city for safety, going to one of the guards that held the circles and desperetly called for help and that one guy, having pity for them, let them inside - just with one condition. The mother would stay in the city and the girls would be safe and sound - as pets to the greats vampires. Without much thinking, their mother kissed them on their forehead and smiled, asking them to take good care of themselves - and Chaerin was too young to even know that was a goodbye. 

And with that her new life began, being prepared to be a pet, only at the age of 15 turning into one at least because of the ual harassment they could have to go through - but she was just a child, nobody would touch her that way. Until, of course she was of age and she turn into a real pet.