Hey there!
Is this while you're trying to work with him or after transformation?
If its before, the plot should progress automatically until you have a midnight encounter with a special figure. After that, talking to Mason to make a foci should progress the plot. Michael is usually in your room.
After the transformation, Michael wanders around and can be anywhere. If you've chosen not to be protected from him, he'll find you when he's ready, much like Mason Domme. But you can talk to him just by wandering until you see a line that Michael is around somewhere and click on the blue part.