Is Kitty feral or stray/abandoned/dumped/homeless? There's a BIG difference.
The new cat in my sig block (Rasputin -
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was homeless. He took time to trust me so he must have some issues from his earlier life, and he certainly was in bad shape when I took him in. He now comes when called and enteres the house through the cat door. But he doesn't seem to want to stay inside with the other cats at night, and he trots back out to his shed. As he seems happy there I have not forced the issue. I started leaving his food for him to come to, then calling him to be fed outside, then finally enticing him just inside the open door to eat. Now he lets himself in for meals, but always goes back out. He has established a "home" in the shed where he feels safe and is obviously comfortable there. On their recent visit to the vet for vaccinations, Ras was the best behaved of them all! He really does have a very sweet nature, and I think in time he will move into the house. But he is NOT feral, just a stray who needed a home.
Sadly this is not likely to be the case with a true "feral" cat. A feral cat may stick around and become calmer, but they will never be truly domesticated. I have "owned" a few feral felines over the years and they always stayed on their own terms. They came to accept me over time but none (of the three) ever became truly domesticated or accepting of other people or cats. I let them stake out their own territory and maintain some distance, so they were OK with that. The one I had to rehome when I joined the Air Force I sent to a friend's farm where she had a big warm shed all to herself, and regular meals in her new home. She lived a long and happy life there, but never became a true pet.
If your kitty is truly feral, you may have to accept a similar situation.