If it is the same Kubota that is used as a basis for the Beta BD722 then yes it could be that the anode is where the Beta has one--on the front of the heat exchanger at the end of the bolt that is on the right.
I have a 21 HP Nanni diesel engine called 3.75 (2 years old) . I have been told by two different distributors (one in Norway and on in France) that there should be no anode within the engine.