The defender made 11 appearances as James McPake’s side sealed their return to the Championship.
And Otoo is now set to join them there after Dunfermline and Celtic agreed terms for his transfer.
Courier Sport understands the deal should be confirmed early next week.
Otoo will become the Pars’ second summer signing from an Old Firm B team, following in the footsteps of Kane Ritchie-Hosler, who joined from Rangers in May.
Like Otoo, Ritchie-Hosler aided Dunfermline’s title chase last season whilst on loan at East End Park.
And the signing of his Celtic counterpart will delight the ex-Ger, who earlier in the summer revealed: “I am trying to convince him to come back! But it is down to him. I want him to come back, of course.”