Signed from PSG in the final days of the summer market, Donnarumma was instantly installed as City's No. 1 by manager Pep Guardiola.
He told La Gazzetta dello Sport: "I already feel at home at City, even though it's not been long since I arrived. They really wanted me, they made me feel important, and now they already consider me one of them."
On Guardiola, he continued: "When you listen to him, you're spellbound. I imagined it like this, but the reality is even better than I could have imagined."
The 26-year-old then added: "I hope to stay in Manchester as long as possible, to have a truly unique experience."