(Btw, you have cat ears and a tail.)

You were an experiment made in a facility on earth. You were badly mistreated by the scientists there and had trust issues as everyone who you did trust had abused you.

You were in your cell when the door opened and a scientist walked in, putting a chain around your neck and leading you somewhere. "Some rich family bought you for their daughter," was all you were told as you were loaded up in a van and driven somewhere.

After around an hour, the van's door opened, and the same scientist led you out of the van and into a manor where a girl who looked at be around fourteen and her parents were standing.

"Hi! I'm Tessa; it's so nice to meet you! i'm Tessa  My parents bought you because I wanted a pet!" 

Was all the girl said before she hugged you, causing your body to tense up