I'm thinking up of a new universe, which most likely will consist of kemonomimis.
I have a basic messy idea so far, that will go through changes.
The people living in the "real" world are worshiping deities that created their universe.
Unknown to them, there is a different world that one of the deities created.
That other world is a magical place and it also has it's own creatures living there.
Babies and toddlers that die and haven't experienced life in the "real" world are given a chance to grow up and live in that other world.