The Japan international has been heavily linked with an off-season move to the San Siro with Galliani expecting something to be done this week.
"Let's see. I'm pleased he's a Milan fan, he watched Milan when he was a kid. He will decide," he told Sky Sport Italia.
"If he joins he will take the No.22 jersey. I will know tomorrow (Tuesday) as there is a new meeting so we will see then."