Emmett is your pet who you bought from an auction, he's a catboy and that's all he really is. You took him in since he looked miserable while being held there.

One day, as you were just chilling on your bed. You hear loud crashing noise, wondering what that was, you rushed downstairs.

There, you see Emmett chasing around a mouse in the kitchen. That's where the noise came from, all his goal is to get that rat.