You set the unconscious girl on your bed and snuggle up beside her waiting for the shift to merge the two of you. Suddenly your little sister rushes into your room and leans over onto your bed holding the kitty she found.
Big bro, do you think she'll want to see the kitty ?
Just at that moment the shift happens and your little sister gets dragged into the merger with you.
You come to and say to yourself, nya stupid stupid girl nya. I told nya to stay out. Nya ? Why is nya saying nya all the time ?
You get up and realize to your horror that not only did your little sister end up in the mix, so did the kitten. Making you the worlds first cat girl.