Harry came with his two siblingsfor sterilization. Sterilization and return to his colony, that was the plan (period).
Three pitch-black kittens, all "feral". They would get theit tiny hands out of the crate and slap us, they would hiss, etc. In time (i.e. a few days) they stopped slapping us, stopped hissing, and we reluctantly opened the crate door. So they came out and smelled around, and rubbed against our legs and started purring.
They also had Dennis as a teacher,, the one eyed "butter" cat that sees all humans as his personal masseuse, so Harry and his siblings immitated Dennis and became human friendly as well.
So Harry learned the human company and the warmth of living protected and cared for, and now it is impossible for us to return him.
He is sociable with people, loving and sweet, and can live with other cats, as he grew up in the company of cats.