Is it possible to cast shadows into a mesh that is not visible?

That is the Hidden Shadow. That only works for the mesh that is casting.
In this case im trying to hide the floor, that if hidden it also hides the shadows cast into it.
I’d like to hide the floor, yet still see the shadows of the characters and everything.
It seems the only way to do this is to actually make some fake shadows as sprites, which is really bad.