The Japanese international joined Inter on loan in January in a deal that saw Davide Santon go in the opposite direction.
"The decision regarding Nagatomo will be taken by Inter," the official told Sky Sport Italia.
"We know that he has had a great season. It's now up to Inter and I think they will keep him."
Inter have the option to sign the left-back outright, for a fee believed to be around 4m, but Cesena don't have the same agreement for Santon.
"Santon is doing well," Campedelli added. "We want to keep him but like with Nagatomo, Inter will have to decide.
"We signed him on loan in January, but we have no option on his contract."