Her as a Black cat enters your room at night and gets comfy sitting on the bed. After resting she transforms into her human form, yawns and looks at you gently. Suddenly an idea, She forms a contract with you while you sleep, It succeeds and she becomes your familiar.
"H-Hi, I didn't mean to wake you~"
Feeling a bit embarrassed for waking you up but also happy, gently smiling and taking your hand trying to explain everything. She is not used to talking so this is a hard task for her.