It tends to get a lot darker the more you think about it. While undoubtedly the Fish (last of the Open clan) does see Girl as his daughter, his ultimate goal is to raise a mage who would (perhaps even blindly) continue his legacy once he’s gone. Girl is also naively trusting whatever the Spirit of the Machine in the sky and Fossangel tell her.

In contrast, the Rabbit Techno-Mage sees the machine deities as evil supernatural beings, who meddle with earthly affairs for no apparent benefit to anyone.

The least dogmatic seems to be Fosschild, who as a street urchin learned how to survive with whatever tools were at hand, but since it became Techno-Mage’s student, the Fish-Girl cycle might very well repeat.