Where Faker is an exorcist (maybe a senior exorcist/high ranking exorcist/paladin) and Deft is a tired fox spirit.
They actually went to HS together, that's why Faker found him familiar the first time they met. Quite a memorable event as Deft just insta runs away because he's too lazy to deals with Humans let alone Exorcists that brings nothing but trouble.
Intrigued by the non-violent spirit, Faker keeps popping up on random occasions to Deft's shrine, even enamoring (*cough* bribing the young inugami Keria) for information about Deft. When that happens, Deft would flick Faker out of the Shrine Boundary, gently setting him down. Though when he is in a bad mood, an extra pillow to the face is what Faker gets.
Deft was originally a half-kitsune, his human blood was more dominant than his spirit inheritance. However, when his elder passed away, his kitsune bloodline awakened and he had to take charge of the shrine and sanctuary.
I'm not good at coming up with issues/problems when writing stories. Maybe they could just roam together (Deft reluctantly pulled everywhere by Faker) to eradicate blood thirsty demons, discipline rowdy deities, and catch villains who dares mess with the inhabitants of Deft's shrine.