City made a bid in the region of £100million for Kaka during the January transfer window, but the playmaker opted to stay loyal to Milan.
Kaka admits his desire to make history at Milan and the support he received from the club's fans made him decide to stay.
"What I represent for Milan and what I have achieved and still want to achieve with Milan was a big factor in my decision," Kaka told Sport TV.
Kaka revealed the demonstrations from fans asking him to stay also played a role, especially during the match between Milan and Fiorentina in the midst of the negotiations.
"Everything was very moving," Kaka said. "From the time I got to the stadium to the time I entered the field. During the entire match it was very moving, I couldn't focus."
Kaka admitted he felt an obligation to listen to the offer from City after Milan agreed to the deal.
"Milan doesn't usually sell players," noted Kaka. "When the club opened the possibility, out of respect I needed to at least hear what they had to offer."